| mind uploading research group |
| Directing Neuronal Growth through Lithographic Patterns | |
| Sun Aug 26 22:49:27 EDT 2001 | rak@minduploading.org |
|
The following article describes recent results at achieving the directed
growth of biological neural networks by using lithography to establish
paths. This is a technique that may be useful to whole brain emulation
and neuronal prosthetics research as a means of testing biological
components in the search for significant parameters and successful data
extraction.
"Chip lithography harnessed to grow living brain cells" "In an attempt to decipher the communications codes used by mammalian brain cells, University of Illinois researchers are using chip lithography to ``microprint'' furrows that growing brain cells will follow when budding inputs (dendrites) and outputs (axons). ``Our nerve cells remain viable for up to one month while maintaining compliance to the microstamped patterns,'' he said By controlling the cell's response, Wheeler hopes to improve on today's medical implants, which tend to lose electrical sensitivity over time. ``We hope to improve the long-term stability of biological activity in implants,'' he said. ``Also, because the brain has ordered layers of cells, we believe that developin techniques for maintaining the orderly growth of the neurons in culture will lead to greater insight into brain activity itself.''" Full Story: http://www.eetimes.com/story/OEG20010821S0053 | |
| Characterizing parameters and their importance in neuronal circuitry | |
| Wed Aug 15 13:35:30 EDT 2001 | rak@minduploading.org |
|
This is probably the last installment of the editorial posts with regards
to the theme of the week on Significance
(http://minduploading.org/themes.html).
The next theme will most likely be selected later today or tomorrow.
Some specific approaches to the characterization of parameters and their importance in neuronal circuitry
And a special tidbit for those of us involved with the NematodeUpload project (http://minduploading.org/research.html#nematodeupload): ROSS - Reconstruction of Serial Sections (http://biocomp.arc.nasa.gov/ross/). | |
| X-Ray Microscopy References | |
| Mon Aug 13 13:58:22 EDT 2001 | rak@minduploading.org |
|
Many thanks to Dr. Richard Gordon for the microscopy references, which
are now available through the articles link under the microscopy heading
of the references page
(http://minduploading.org/references.html) at:
http://minduploading.org/articles.imag.html
If you cannot obtain these articles, you can try contacting the authors for reprints, or you may contact me (rak@minduploading.org) to arrange a copy where possible. (I currently have electronic copies in PDF format of the Uo, Vogt and Weiss papers.) | |
| Distributed Computing | |
| Sat Aug 11 17:14:34 EDT 2001 | rak@minduploading.org |
| Seeing as Eugene is very interested in setting up a distributed computing solution such as a Beowulf system for the NematodeUpload project, and I am looking into parallelization of my emulation code, the following page on Dr.Dobb's journal site could have some valuable information: Distributed Computing (http://www.ddj.com/topics/distrib/papers.htm?topic=distrib). | |
| Multiple Regression | |
| Sat Aug 11 10:05:37 EDT 2001 | rak@minduploading.org |
| In the most abstract sense, finding the right set of parameters with which to build a whole brain emulation involves regression. An introduction to multiple regression is available through the following link: http://www.statsoftinc.com/textbook/stmulreg.html | |
| Quick Links: Significance and Genetic Algorithms | |
| Fri Aug 10 14:01:45 EDT 2001 | rak@minduploading.org |
|
Some quick links that continue our interlaced threads on
significance (http://minduploading.org/themes/significance.html)
and the utility of genetic algorithms.
Molecular Information Theory and the Theory of Molecular Machines (http://www.lecb.ncifcrf.gov/~toms/) This site describes the use of Information Theory in molecular biology. While the topic is on a mild tangent to whole brain emulation research, we face some very similar issues in the same domains. The techniques that are discussed aim to determine significant information that is conveyed and transported. The results obtained with information theoretic approaches also have implications for the development of molecular-level technology. Digital Biology (http://www.digitalbiology.com/) Aimed at the creation of artifical life, this site includes a demonstration of a simple genetic algorithm that can evolve the architecture and connection weights of a neural network. For an encore, see the home page of William M. Spears (http://www.cs.uwyo.edu/~wspears/). Statistical Data Analysis: Inferring From Data (http://ubmail.ubalt.edu/~harsham/stat-data/opre330.htm) This is a comprehensive site about statistical data analysis techniques. Knowledge Discovery In Biology and Medicine (http://bioinfo.weizmann.ac.il/cards/knowledge.html) Data mining is explained as a strategy to obtain functions that can be used to support decision making from vast stores of available data. Examples include the search for functions in Functional Genomics, such as the GeneCards Project (http://bioinfo.weizmann.ac.il/cards/background.html). This is part of the field of Bioinformatics (http://bioinformatics.weizmann.ac.il/cards/bioinfo_intro.html). | |
| Merkle: Large Scale Analysis of Neural Structures | |
| Fri Aug 10 08:15:46 EDT 2001 | rak@minduploading.org |
|
Ralph C. Merkle describes the analysis of neural structures, with an emphasis on reconstruction from data obtained through microscopy. Take note especially of section 2, the first paragpraph of which is reproduced below. This document gives us some background and references that are clearly relevant both to the ongoing NematodeUpload project and this week's Theme on Significance.
Large Scale Analysis of Neural Structures Ralph C. Merkle Reconstructions of neural structures of up to hundreds of neurons [1, 2, 10, 11, 13, 14, 15, 16, 19, 31, 33, 34, 124, 111, 149] (and even the reconstruction of sub-cellular organelles [3, 30, 326, 327, 328]) have been done by examining sections of neural tissue with either light or electron microscopy. Most dramatic was the complete reconstruction of all 959 cells in the nematode [349] including the 338 cells in its nervous system [350, 351], as well as their complete lineage from the fertilized egg. This work all required the very tedious analysis of the images by a human -- to date, there has been no successful fully automated reconstruction of neural tissue (although Hibbard et al. [339] successfully completed a fully automated reconstruction of a capillary bed -- the lumen of the capillary is sufficiently distinct that current image analysis techniques work). In light microscopic work an entire cell body is injected with contrast material -- sometimes fluorescent. The presence of even fine fibers can be detected this way, although their dimensions (sometimes as small as .1 micron) and fine structure cannot always be accurately determined. A single neuron can be traced in a section as thick as a few hundred microns. The X and Y coordinates can be entered into a computer by centering a cross hair or other computer- coupled pointing device on the feature of interest. Depth (or Z- axis) information can be recovered by using a microscope with a shallow depth-of-field, and measuring the focus adjustment at which the feature of interest produces a sharp image. Report CSL-89-10 November 1989, [P89-00173], Xerox Palo Alto Research Center Abstract and Article: http://merkle.com/merkleDir/brainAnalysis.html | |
| Links for WBE/MU | |
| Fri Aug 10 08:00:57 EDT 2001 | rak@minduploading.org |
| More links at minduploading.org/links.html! I have been holding these back for a while (months, really), because I intended to inspect each link and categorize them. Time is at a premium, so I never did complete that. If you have some spare time, I would be delighted if you could send me one-liners describing more of the links. Of course, you can also go ahead and run your own (and up-to-date) searches to augment the list. If you forget the URL above, you can also reach this list of links through the ``Miscellaneous'' section on the References page (minduploading.org/references.html). | |
| Theme of the Week: Significance | |
| Thu Aug 9 12:25:24 EDT 2001 | rak@minduploading.org |
|
Minduploading.org Weekly Themes: On a trial basis, I will be picking a theme - generally from current discussions on MURG - on a weekly basis. In an effort to stimulate constructive discussion and the generation of applicable results, that theme then reappears with News stories and Featured Sites for 7 days. Hopefully, at the end of the week there will be a better understanding, perhaps some consensus and a few links in the References and Resources section.
Activity on MURG is fairly slow this week (and a blistering hot week it is!), so I'll pick a theme from my own posts. This week's theme is: Significance: Determining what to Emulate. | |
| Research page and NematodeUpload project | |
| Thu Apr 12 10:48:26 EDT 2001 | rak@minduploading.org |
|
The Research page has been opened at minduploading.org. This page will
serve as a central location for research projects of individuals or
collaborations involving MURG members and aimed
at whole brain emulation. Eventually, many specific project sites will
branch out from links at this location. At present, only the NematodeUpload project is
represented there.
I have taken some of the links that were recently posted on MURG as background information for the project. Many important links and resources are still missing, so please send me suggestions! If you have a better write-up describing the project, please send me that also. I added a few links of my own, such as WormBase. Some of the main links, as well as a link to the research project have also been added to the references and resources page. | |
| HAL FPGA Computer | |
| Thu Mar 29 13:19:13 EST 2001 | rak@minduploading.org |
|
Yes, the FPGAs are back again! This time it looks like NASA actually
has a working product for use in many implementations. The HAL
computer series. A contender for whole brain emulation (neurological
reconstruction and emulation, or CA based)? Certainly!
"Real-life 'HAL' signals major step" "The way the real HAL's creators describe it, this computer has the ability to possess human --even superhuman -- qualities, to process information faster than the human brain." "HAL stands for Hyper Algorithmic Logic, a product of 3-year-old Midvale, Utah-based Star Bridge Systems Inc. Star Bridge calls HAL the first "hypercomputer," able to conduct billions of operations at the exact same time, within a second, "thinking like the brain thinks and working like the universe works," according to Kent L. Gilson, Star Bridge's founder and chief executive, who presented the system Tuesday to Langley researchers." [...] "HAL contains a "reconfigurable" computer chip that can change functions in a split second and build them right into its hardware. Star Bridge created an operating system called Viva (meaning "life") that allows a user to program specific information for a specific task, exponentially increasing the computer's efficiency and speed so it can carry out many tasks at once. It all" Complete Story: http://dailypress.com/business/stories/06809sy0.htm | |
| Humbled by the Genome's Mysteries | |
| Mon Feb 19 11:38:02 EST 2001 | rak@minduploading.org |
|
Homo Sapiens possesses between 30,000 and 40,000 genes, insufficient to encode over 140,000 messages in a one-to-one mapping. Interesting! Perhaps genetic codes, much like memory in neuronal circuitry, is a (parallel) distributed code! Well, let's wait to hear what the geneticists say --- apparently there is much room in a single gene's coding and non-coding sections. :)
"Humbled by the Genome's Mysteries" (by Stephan Jay Gould) "The general estimate for Homo sapiens - sufficiently large to account for the vastly greater complexity of humans under conventional views - had stood at well over 100,000, with a more precise figure of 142,634 widely advertised and considered well within the range of reasonable expectation. Homo sapiens possesses between 30,000 and 40,000 genes, with the final tally almost sure to lie nearer the lower figure. In other words, our bodies develop under the directing influence of only half again as many genes as the tiny roundworm needs to manufacture its utter, if elegant, outward simplicity." "Human complexity cannot be generated by 30,000 genes under the old view of life embodied in what geneticists literally called (admittedly with a sense of whimsy) their "central dogma": DNA makes RNA makes protein - in other words, one direction of causal flow from code to message to assembly of substance, with one item of code (a gene) ultimately making one item of substance (a protein), and the congeries of proteins making a body. Those 142,000 messages no doubt exist, as they must to build our bodies' complexity, with our previous error now exposed as the assumption that each message came from a distinct gene." Complete Story: http://www.nytimes.com/2001/02/19/opinion/19GOUL.html | |
| Cheap large amounts of memory | |
| Wed Feb 14 12:27:38 EST 2001 | rak@minduploading.org |
|
Could it be? Finally cheap memory extensive enough to support some real
neurological reconstruction and whole brain emulation efforts?
"Scientists in memory advance" "The fourth and most interesting invention produces a memory system that enables up to 10.8 terabytes of data to be stored in an area the size of a credit card, with no conventionally moving parts. Each square centimetre of this memory system is a closed unit containing a metal oxide material on which data are recorded, and a reader made of a fibre optic tip suspended above the material in a lubricant. The company said the system could be produced commercially within two years, and each unit should cost no more than $50 (£34) initially, with the price likely to drop later. The company is seeking partners to produce the units."
Complete Story: http://news.ft.com/ft/gx.cgi/ftc?pagename=View&c=Article&cid= | |
| Featured Site: The Virtual Brain Machine Project | |
| Wed Jan 3 12:14:52 EST 2001 | rak@minduploading.org |
| Bruce Adams' site on ``The Virtual Brain Machine Project'' has become this month's Featured Site (minduploading.org/featured-site.html). | |
| FAQ Coming Together | |
| Thu Dec 14 17:52:08 EST 2000 | rak@minduploading.org |
| Well, I've finally started to put together that FAQ (minduploading.org/mu-faq.html). I'm still merging some information in, and I'm sure that very many relevant Q-and-A's are missing. Please go take a look and let me know what should be added or changed. (Yes, Jesse, I'm still including some more of that stuff you posted to the mu-faq mailing list at SourceForge.) | |
| Number Crunching: Brain Simulation | |
| Tue Dec 12 11:43:59 EST 2000 | rak@minduploading.org |
| Bruce's page on the number crunching requirements for Brain Simulation has been added to the References section of minduploading.org. It's a very honest effort, please do go take a look! | |
| Featured Site: Karel Svoboda Lab | |
| Wed Dec 6 15:52:38 EST 2000 | rak@minduploading.org |
| The newest reference has been added to the Featured Site page. This time the spotlight is on Karel Svoboda's lab and their impressive efforts at visualizing intact neuronal circuitry. | |
| Perfect Lenses? | |
| Sat Nov 11 22:20:11 EST 2000 | rak@minduploading.org |
|
Dr. Pendry postulates the properties of lenses made with materials that have a negative refractory index and subsequently may permit the construction of perfect lenses at any wavelength of light. If this works, it could be of hugh value to whole brain emulation. Imagine extreme precision at long wavelengths! This could reduce the damage to a sample, possibly even aid in the development of non-invasive high-resolution scanning devices.
"Lens design: A sharper focus" "THEORETICAL physicists have a knack of asking ``why not'' Antimatter was discovered because a theoretician called Paul Dirac saw that one of his equations had two solutions: one with a plus sign that predicted normal negatively charged electrons, the other with a minus sign that predicted a curious positively charged beast." "In similar vein, John Pendry of Imperial College, London has been asking what happens if a material's refractive index, which measures how much it bends a ray of light or other form of electromagnetic radiation, is negative instead of positive -- an idea that folk familiar with practical optics might dismiss as absurd." "Dr Pendry's calculations for a material with a negative refractive index, rather like Dirac's for the electron, have two solutions -- and the second allows near-field waves to grow instead of decaying. In the right circumstances this effect can exactly balance out the decay, ensuring that all the information is restored in a perfect image of the source. The wavelength of visible light is a fraction of a millionth of a metre, which sets a resolution limit for conventional optical microscopes. But with negative-refractive-index lenses, this limit could be removed." "Earlier this year, Sheldon Schultz at the University of California, San Diego, showed that a specially designed material made of wires and rings had a negative refractive index in the microwave region. Meanwhile Dr Pendry and his colleagues at Hammersmith Hospital in London, along with GEC Marconi, an electronics company, have designed a negative-refractive-index lens for radio waves on the same principles." "The technique remains unproven, but early efforts by Dr Pendry and his colleagues seem promising. And Dr Pendry already has ideas about how to build lenses that would do the same job in the optical region. For generations of scientists, the diffraction limit was seen as a fundamental barrier to progress in optics, so news of perfect lenses will come as a shock to some. But then, so did antimatter." Complete Story: http://www.economist.com/science/displayStory.cfm?Story_ID=417791 | |
| Massively Parallel Processor on a Chip | |
| Tue Oct 10 19:45:38 EDT 2000 | rak@minduploading.org |
|
An interesting platform for whole brain emulation. Today, the German company PACT made a surprise announcement at the Microprocessor Forum in San Jose, presenting its massively parallel processor design: the XPP. Their first implementation allows 128 individual processors to exist on a single chip. At 100MHz, the chip can thereby achieve 50 giga operations per second. The chip is reconfigurable, adapting itself directly to the desired algorithm, a variation on the FPGA theme.
Complete Story: http://www.heise.de/newsticker/data/jow-10.10.00-000/ (in German) | |
| Directly interfering with specific memories by applying complex magnetic fields | |
| Mon Oct 2 15:53:27 EDT 2000 | rak@minduploading.org |
|
The following article presents the results of tests involving the effect
of very specific electromagnetic fields on memory. Electromagnetic fields
with the properties of hippocampal theta bursts and amygdaloid burst
firing were successfully employed to induce the forgetting of recently
acquired fear conditioning in rats. This is a rough, but real example of
direct interference with and possible assertion of brain-states and the
intermediate stages (synaptic potentiation) of memory.
Exposure to a theta-burst patterned magnetic field impairs memory acquisition and consolidation for contextual but not discrete conditioned fear in rats B. E. McKay, M. A. Persinger, and S. A. Koren Preceding or immediately following fear-conditioning rats were exposed for 30min to either a sham field, one of two symmetrical (sine-wave 7, 20Hz) magnetic fields or to one of two complex magnetic fields whose waveforms were modeled after salient electrophysiological patterns within either the hippocampal formation (theta-burst) or the amygdaloid complex (burst-firing). The magnetic fields were presented in successive 2s intervals through each of the three spatial planes and then simultaneously within all three planes. Field strengths ranged between 0.5 and 1 microTesla. Only the group exposed after the conditioning to the theta-burst (hippocampal) magnetic fields displayed evidence of forgetting, as inferred by their marked attenuation of freezing behavior, during contextual extinction 24h later. This powerful treatment explained 75% of the variance in the extinction scores. Behavioral responses to the discrete conditioned stimulus were not affected. These findings are consistent with the involvement of the hippocampus in learned fear to contextual stimuli but not to discrete auditory stimuli and suggest that physiologically relevant stimuli may be delivered to the brain by weak, complex magnetic fields whose intensities are ubiquitous within modern environments. Neuroscience Letters, 2000, Volume 292, Issue 2, Pages 99-102 Abstract and Article: http://neuroscion.com/abstract/JOURNAL.NSL.nol0131a_03043940_v0292i02_00014373 | |
| Researchers Trace Roots Of Vivid Memories | |
| Fri Sep 29 09:38:30 EDT 2000 | rak@minduploading.org |
|
The following research may add some support to the camp within MURG that
feels complete emulation of both high-level brain areas and sensory regions
of brain is necessary. While it has long seemed reasonable to many
researchers, and similar findings have been made in other recordings, fMRI
has now shown clearly that the recall of vivid memories involves
reactivation of sensory regions.
"Researchers Trace Roots Of Vivid Memories" "Researchers have found that calling up vivid memories—the face of a loved one or the chords of a favorite song— activates regions of the brain responsible for processing sensory experiences. When a person recalls a vivid memory, some of the sensory regions of the brain responsible for etching the original memory are reactivated." "[...] investigator Randy L. Buckner, Mark E. Wheeler and Steven E. Petersen at Washington University in St. Louis describe how they used functional magnetic resonance imaging (fMRI) to probe the roots of a longstanding hypothesis in the field of memory research. According to the reactivation hypothesis, brain regions that are activated when a person has a sensory-specific experience are reactivated whenever the person remembers that experience." Complete Story: http://www.hhmi.org/news/buckner.html | |
| News back online | |
| Fri Sep 1 09:19:26 EDT 2000 | rak@minduploading.org |
| News back online The sendmail installation on the workstation here that has all the scripting capability used for news submissions has been re-activated, so that News processing can finally continue! Hurra! | |
| MIT, NYU Researchers Create First Designer Biomaterial For Growing Mammalian Nerve Cells | |
| Tue Jun 20 09:31:16 EDT 2000 | A.Koene@phys.uu.nl |
|
Growing neurons on biomaterial scaffolds.
"MIT, NYU Researchers Create First "Designer" Biomaterial For Growing Mammalian Nerve Cells" "CAMBRIDGE, Mass. -- Researchers at the Massachusetts Institute of Technology and New York University report in the June 6 issue of the Proceedings of the National Academy of Sciences (PNAS) that they have made a biomaterial that supports living nerve cells." "This peptide-based scaffold, on which neurons grow fibers to communicate with each other and establish functional synapses, may be the long-sought ideal medium for growing replacement nerve cells for victims of spinal cord injuries and other forms of nerve damage." "The new biomaterial developed by Zhang, Holmes and colleagues seems to be an ideal substrate, or growing surface, for cells slated for replacing damaged tissue in the nervous system. Neurons attach to it and grow axons, the long tails through which they send signals. Active synapses -- the spaces through which nerve cells communicate -- form and survive in these cultured cells." "Fragments of the 80,000-plus of kinds proteins in our body are called peptides. Peptides transform themselves like tiny smart Legos into millions of essential substances." "Zhang and other scientists have recently discovered that these same peptides can be tweaked into forming completely new natural materials that may be able to perform a variety of useful functions inside and outside the body." "Further tests showed that nerve cells happily grew on these fibers. While no immune response or inflammation was seen when the peptides were injected into rat muscle tissue, they have not yet tested in the brain, spinal cord and peripheral nerves." Complete Story: http://www.sciencedaily.com/releases/2000/06/000607073955.htm (or http://web.mit.edu/newsoffice/nr/2000/biomaterial.html) | |
| Immortality, Anyone? | |
| Mon Jun 19 13:36:28 EDT 2000 | A.Koene@phys.uu.nl |
|
The ethics of immortality, as debated in letters sent to Science
(Vol.288, No.5470, p.1345).
"Immortality, Anyone?" "I hope for John Harris's sake (as well as my own) that his predictions of therapeutic immortality (Essey, ``Intimations of immortality,'' Science's Compass, 7 Apr., p.59) will come true soon. But I fear that his planned ethical controls will not run smoothly. In the not-too-distant future, one of his counseling sessions at ``Telomeres R Us'' might run something like this:"
"John Harris: congratulations, sir! I hear your treatment was successful
and that you are now a wealthy immortal. This is just one or the replies at Science's dEbates on Harris's Essay ``Intimations of Immortality''. Complete Story: http://www.sciencemag.org/cgi/content/full/288/5470/1345 | |
| Role of Rapid Dendritic Protein Synthesis in Hippocampal mGluR-Dependent Long-Term Depression | |
| Mon Jun 19 13:23:41 EDT 2000 | A.Koene@phys.uu.nl |
|
Evidence of the physiological changes underlying structural changes due to
Long-Term Depression (LTD).
Role of Rapid Dendritic Protein Synthesis in Hippocampal mGluR-Dependent Long-Term Depression K.M.Huber, M.S.Kayser and M.F.Bear "A hippocampal pyramidal neuron recieves more than 10^4 excitatory glutamatergic synapses. Many of these synapses contain the molecular machinary for messanger RNA translation, suggesting that the protein complement (and thus function) of each synapse can be regulated on the basis of activity. Here, local postsynaptic protein synthesis, triggered by synaptic activation of metabotropic protein receptors, was found to modify synaptic transmission within minutes." "Two points are considered axiomatic in the neurobiology of memory: first, that the elementary unit of information storage is the synapse, and second, that information is stored as a physical change in the brain. The discovery of polyribosomes at the base of individual synapses has long invited speculation that local protein synthesis is involved in activity-dependent, synapse-specific structural modifications that store information. Our results demonstrate that local protein synthesis is involved in the coupling of mGluR activity to an enduring, synapse-specific modification of synaptic transmission. The mGluR-LTD model should be useful for dissecting the mechanisms of synaptic mRNA translation regulation and their contribution to structural plasticity and information storage in the mammalian brain." Science, vol.288 No.5469 pp.1254-1256 Abstract and Article: http://www.sciencemag.org/cgi/content/abstract/288/5469/1254 | |
| Optical probing of neuronal circuits with calcium indicators | |
| Wed Jun 7 09:25:20 EDT 2000 | Eugene Leitl |
|
A new and intriguing way to map neuronal circuitry through calcium imaging.
Optical probing of neuronal circuits with calcium indicators Zita A. Peterlin, James Kozloski, Bu-Qing Mao, Areti Tsiola, and Rafael Yuste An experimental difficulty in unraveling circuits in the mammalian nervous system is the identification of postsynaptic targets of a given neuron. Besides ultrastructural reconstructions, simultaneous recordings from pairs of cells in brain slices have been used to identify connected neurons. We describe in this paper a technique using calcium imaging that allows rapid identification of potential postsynaptic targets. This method consists of stimulating one neuron ("trigger") while imaging a population of cells to detect which other neurons ("followers") are activated by the trigger. By using bulk-loading of calcium indicators in slices of mouse visual cortex, we demonstrate that neurons that display somatic calcium transients time-locked to the spikes of a trigger neuron can be monosynaptically connected to it. This technique could be applied to reconstruct and assay circuits in the central nervous system. Proc. Natl. Acad. Sci. USA, Vol. 97, Issue 7, 3619-3624, March 28, 2000 Abstract and Article: http://www.pnas.org/cgi/content/abstract/97/7/3619 (Ed. rak@minduploading.org: This reference has been added to minduploading.org/mu-articles.html for its relevance and potential significance to core concerns of whole brain emulation research.) | |
| Neuronal growth in the brain may explain phantom limb syndrome | |
| Tue May 23 12:55:31 EDT 2000 | jesse@bernztech.org |
|
Story about further understanding of sensory input and
neuro/synaptogenesis:
"Neuronal growth in the brain may explain phantom limb syndrome" "One of the most troubling aftereffects of an arm or leg amputation is the phantom limb syndrome, in which the person reports receiving sensations from the lost limb. Neuroscientists at Vanderbilt University report the first direct evidence that significant growth and reconnection of neurons in the brains of amputees may be at the root of this problem." "The researchers found clear evidence that neurons from the face area in the brainstem had extended axons and made a number of connections in the hand area. Although the number of such connections was limited there were enough to activate many of the neurons from the hand area, the researchers found." Complete Story: http://www.vanderbilt.edu/News/news/apr00/nr26.html | |
| Brain-computer interfaces: Give It A Thought -- And Make It So | |
| Tue May 23 12:53:18 EDT 2000 | jesse@bernztech.org |
|
Brainwaves have been readable for a while, but previously only in
strict laboratory settings.
"Give It A Thought -- And Make It So" "While several teams around the world are working on brain-computer interfaces (BCI), computer science graduate student Jessica Bayliss is the first to show that detection of the brain's weak electrical signals is possible in a busy environment filled with activity. She has shown that volunteers who don a virtual reality helmet in her lab can control elements in a virtual world, including turning lights on and off and bringing a mock-up of a car to a stop by thought alone." Complete Story: http://www.rochester.edu/pr/releases/cs/bayliss.html | |
| The development of sight and sound | |
| Tue May 23 12:49:01 EDT 2000 | jesse@bernztech.org |
|
A very interesting piece on the plasticity of brain ``wiring'' (or maybe
I just like it because it involves rewiring ferrets). [Ed.
rak@minduploading.org:] In a similar vein, previous research has
shown that the brain ``recycles'' its circuitry in the case of sensory
loss. E.g. loss of sight can lead to an expanded auditory and touch
sensitive brain area, reusing neurons previously allocated to vision.
"Rachel Smyly looks into new research on how the parts of the brain that deal with sight and sound develop." "Our eyes, ears and indeed all our sensory organs send information to our brains in the same way as electrical impulses in nerve fibres. New research now suggests that, just after birth, these signals help to wire up the parts of the brain that will decode them." "The brain’s auditory cortex decodes sounds and is built differently to the visual cortex. But if signals from the eyes (intended for the visual cortex) are redirected to the auditory cortex they can remould the neurons of their unexpected destination into the shape of the visual cortex." Complete Story: http://helix.nature.com/nsu/000420/000420-13.html | |
| Identification of sleep-promoting neurons in vitro | |
| Tue May 23 12:37:32 EDT 2000 | jesse@bernztech.org |
|
This item directly relates to some relations between electric/chemical
brain activity and resultant mental state; it may also indicate study
eventually leading to understanding levels of consciousness.
Identification of sleep-promoting neurons in vitro THIERRY GALLOPIN, PATRICE FORT, EMMANUEL EGGERMANN, BRUNO CAULI, PIERRE-HERVÉ LUPPI, JEAN ROSSIER, ETIENNE AUDINAT, MICHEL MÜHLETHALER & MAURO SERAFIN The neurons responsible for the onset of sleep are thought to be located in the preoptic area and more specifically, in the ventrolateral preoptic nucleus (VLPO). Here we identify sleep-promoting neurons in vitro and show that they represent an homogeneous population of cells that must be inhibited by systems of arousal during the waking state. We find that two-thirds of the VLPO neurons are multipolar triangular cells that show a low-threshold spike. This proportion matches that of cells active during sleep in the same region. We then show, using single-cell reverse transcriptase followed by polymerase chain reaction, that these neurons probably contain [gamma]-aminobutyric acid (GABA). We also show that these neurons are inhibited by noradrenaline and acetylcholine, both of which are transmitters of wakefulness. As most of these cells are also inhibited by serotonin but unaffected by histamine, their overall inhibition by transmitters of wakefulness is in agreement with their relative inactivity during waking with respect to sleep. We propose that the reciprocal inhibitory interaction of such VLPO neurons with the noradrenergic, serotoninergic and cholinergic waking systems to which they project is a key factor for promoting sleep. Abstract and Article: http://www.nature.com/cgi-taf/DynaPage.taf?file=/nature/journal/v404/n6781/abs/404992a0_fs.html&filetype= | |
| Featured Site: Anatomically Accurate Neural Networks: Building a Hippocampus | |
| Fri May 19 17:10:52 EDT 2000 | rak@minduploading.org |
| The newest featured site by Giorgio A. Ascoli is available at minduploading.org/featured-site.html. | |
| Rewiring The Damaged Brain | |
| Thu May 11 19:38:41 EDT 2000 | jesse@bernztech.org |
|
Article concerning learning and memory:
"Rewiring The Damaged Brain" "In a study published in Experimental Brain Research, researchers from the Department of Physiology at Adelaide University have discovered that stimulating the nerve from a muscle to the brain can alter the size of responses from the area of cortex that supplies the muscle. Furthermore, these changes last for some time after the stimulation has stopped." "In the study, electronic coils were used to stimulate the cerebral cortex and then measure changes in its activity produced by stimulation of nerves from the fingers. Differently shaped coils have been designed to produce different patterns of stimulation. Held close to a subject’s head, they are non-invasive and painless."
Complete Story: http://www.sciencedaily.com/releases/2000/04/000405230348.htm | |
| New Neurons: Extraordinary Evidence or Extraordinary Conclusion? | |
| Tue May 9 18:55:12 EDT 2000 | rak@minduploading.org |
|
Gould et al. defend their findings that new neurons are produced
and migrate to functional locations in the neocortex of primates
against criticism by Nowakowski and Hayes. They defend their article
well, in my opinion. The likelihood that new neurons are constantly
created, and the additional dynamics this affords the brain, are among
the most important discoveries in the Neurosciences of recent times.
New Neurons: Extraordinary Evidence or Extraordinary Conclusion? Richard S. Nowakowski and Nancy L. Hayes Gould et al. (1) reported that in the adult primate new neurons may be added to some neocortical association areas. This remarkable finding explicitly challenges previous work indicating that the production of new neurons in the primate neocortex is limited to the fetal period (2), and, if true, would force a reevaluation of virtually all current conceptual bases for understanding how neuronal circuitries in neocortex develop and are modified (3). But "extraordinary claims require extraordinary evidence" (4)--and the potential impact of these findings demands a close examination of the chain of evidence constructed by Gould et al. For the overall conclusions to stand, each link in the chain must be unambiguously correct; plausible alternative explanations must be considered and eliminated. Yet each proffered link contains ambiguity or uncertainty, and plausible alternative explanations remain. Elizabeth Gould and Charles G. Gross Response: We agree with Nowakowski and Hayes that for the conclusions in (1) to hold, each link in our chain of logic must be "unambiguously correct," and that "plausible alternative explanations must be considered." We find their account of our work inaccurate, however, and their criticism of our inferences unjustified by data, logic, or literature. Science, Volume 288, Number 5467 Issue of 5 May 2000, p 771 Abstract and Article: http://www.sciencemag.org/cgi/content/full/288/5467/771a | |
| TIME: Will The Mind Figure Out How The Brain Works? | |
| Mon Apr 10 12:28:47 EDT 2000 | rak@minduploading.org |
|
Steve Pinker muses about mind uploading among other things, mentions Joe's destructive mind uploading procedure in detail!
"TIME: Will The Mind Figure Out How The Brain Works?" "Will neurologists scan our brains down to the last synapse and duplicate the wiring in a silicon chip, giving our minds eternal life?" "If you think the answer is obvious, you are prepared for the ultimate triumph of the brain science of tomorrow. The synapse scanner has been perfected, and you can download a backup copy of your mind into a chip that will outlast your brain. Unfortunately the scanner destroys the tissue it scans, so you have to choose between your old brain and a new one. The new brain will react and behave exactly like you--but would it be you? If you say yes, are you confident enough to step into the scanner?" Complete Story: http://www.time.com/time/magazine/articles/0,3266,42360,00.html | |
| Summary and Webcast of Symposium on Spiritual Machines | |
| Sun Apr 2 10:34:09 EDT 2000 | rak@minduploading.org |
|
A Summary (http://slashdot.org/features/00/04/01/2121226.shtml) and the webcast (http://www.technetcast.com/)(*) of the ``Symposium On Spiritual Machines'' are available.
(*) Availability of the webcast may be delayed a couple of days. | |
| Synchronous firing underlies attention | |
| Tue Mar 28 15:01:43 EST 2000 | jesse@bernztech.org |
|
Here is a report from the Krieger
Mind-Brain Institute at Johns Hopkins University about the
physiological cause of attention. If that to which we're attentive could
be called the same as or similar to that of which we're conscious, could
this be preliminary research into the physical nature of human
consciousness? [Ed: rak@minduploading.org] Interesting
question... there's been a lot of ``Attention'' research, but researchers
tend to shy away from the label ``Consciousness'' research. It is certainly
becoming apparent that brain activity is highly oscillatory, and that
oscillatory systems are fundamental to many mental functions - such as
memory for instance. This appears to be quite reasonable, when one considers
that the computational power and complexity of recurrent systems by far
outstrips that of feed-forward systems of equal size.
"Brain Cell 'Chorus' Appears As Attention Increases" "'The nerve cells which represent the important information need a way to stand out from the crowd of other information,' says Peter Steinmetz, lead author on the paper and a former postdoctoral scholar at the institute. 'Firing synchronously – like singers in a chorus -- is one way to stand out from the crowd.'" Complete Story: http://www.sciencedaily.com/releases/2000/03/000308112357.htm | |
| Tensor map of developmental brain growth patterns | |
| Tue Mar 28 14:54:00 EST 2000 | jesse@bernztech.org |
|
This article details the results of an ambitious project to map
progressions of changes in a developing brain.
Growth patterns in the developing brain detected by using continuum mechanical tensor maps PAUL M. THOMPSON, JAY N. GIEDD, ROGER P. WOODS, DAVID MACDONALD, ALAN C. EVANS & ARTHUR W. TOGA The dynamic nature of growth and degenerative disease processes requires the design of sensitive strategies to detect, track and quantify structural change in the brain in its full spatial and temporal complexity. Although volumes of brain substructures are known to change during development, detailed maps of these dynamic growth processes have been unavailable. Here we report the creation of spatially complex, four-dimensional quantitative maps of growth patterns in the developing human brain, detected using a tensor mapping strategy with greater spatial detail and sensitivity than previously obtainable. By repeatedly scanning children (aged 3–15 years) across time spans of up to four years, a rostro-caudal wave of growth was detected at the corpus callosum, a fibre system that relays information between brain hemispheres. Peak growth rates, in fibres innervating association and language cortices, were attenuated after puberty, and contrasted sharply with a severe, spatially localized loss of subcortical grey matter. Conversely, at ages 3–6 years, the fastest growth rates occurred in frontal networks that regulate the planning of new actions. Local rates, profiles, and principal directions of growth were visualized in each individual child. Nature 404, 190 - 193 (2000) © Macmillan Publishers Ltd. Abstract and Article: http://www.nature.com/cgi-taf/DynaPage.taf?file=/nature/journal/v404/n6774/abs/404190a0_fs.html | |
| New Study Identifies Brain Centers For Attention Control | |
| Tue Mar 28 14:50:42 EST 2000 | jesse@bernztech.org |
|
Here is another article on further research into brain morphology. The original article was submitted by the researchers to Nature Neuroscience, so we may see it soon.
"New Study Identifies Brain Centers For Attention Control" "By asking subjects to direct their attention to particular areas in space while their brains were being scanned by MRI, researchers have mapped brain regions active in the high-level neural control of attention. Like an initial satellite reconnaissance of new terrain, this first mapping represents a key step toward understanding the detailed topography and function of brain regions involved in high-level 'executive' control of attention." "[...] Scientists determined that certain discrete brain areas of the cortex invariably showed activity during the attentional tasks. Principal among these areas are the superior frontal, inferior parietal and superior temporal cortex." Complete Story: http://www.dukenews.duke.edu/Research/mangnatr.htm | |
| Death Triggers Regrowth of Zebra Finch Neurons | |
| Tue Mar 28 14:49:06 EST 2000 | jesse@bernztech.org |
|
Understanding neuron regeneration in adults may aid in the development of computer-brain interface.
"Death Triggers Regrowth of Zebra Finch Neurons" "In the 24 February issue of Neuron, neuroscientists report that the brains of adult male songbirds can recruit certain kinds of neurons to grow and replace cells that have died. What's more, the experiments suggest that the new neurons are fully functional. But the recruitment is selective; only certain cells have this phoenixlike quality. Researchers now hope to discover what causes that selective recruitment so that they can eventually trigger the growth of all types of neurons." | |
| Signals from roof plate direct dorsal neuronal development | |
| Tue Mar 28 14:45:13 EST 2000 | jesse@bernztech.org |
|
This article deals with the cells within a developing nervous system.
Developmental biology: Raising the roof Miguel Manzanares, Robb Krumlauf Cells in the developing nervous system rely on signals from specific organizing centres to tell them what they should become. The signals they receive depend on their position in the developing neural tube. Cells in the dorsal part of the neural tube receive signals from the roof plate, and this process involves a gene called Lmx1a. Mouse embryos without this gene or with no roof plate lack specific sets of dorsal interneurons. Nature Volume 403, Number 6771 Issue of 17 Feb 2000 Abstract and Article:http://www.nature.com/cgi-taf/DynaPage.taf?file=/nature/journal/v403/n6771/full/403720a0_fs.html | |
| Repetition Priming dependance on preexisting representations | |
| Tue Mar 28 14:43:28 EST 2000 | jesse@bernztech.org |
|
A discovery concerning the mediation of response, given repeated simuli.
Neuroimaging Evidence for Dissociable Forms of Repetition Priming R. Henson, T. Shallice, R. Dolan Repetition priming has been characterized neurophysiologically as a decreased response following stimulus repetition. The present study used event-related functional magnetic resonance imaging to investigate whether this repetition-related response is sensitive to stimulus familiarity. A right fusiform region exhibited an attenuated response to the repetition of familiar stimuli, both faces and symbols, but exhibited an enhanced response to the repetition of unfamiliar stimuli. Moreover, both repetition effects were modulated by lag between successive presentations. Further experiments replicated the interactions between repetition, familiarity, and lag and demonstrated the persistence of these effects over multiple repetitions. Priming-related responses are therefore not unitary but depend on the presence or absence of preexisting stimulus representations. Science Magazine Volume 287, Number 5456 Issue of 18 Feb 2000, pp. 1269 - 1272 Abstract and Article: http://www.sciencemag.org/cgi/content/abstract/287/5456/1269 | |
| LTP involves delivery of new AMPA receptors to spines | |
| Tue Mar 28 14:19:03 EST 2000 | rak@minduploading.org |
|
A major mechanism underlying plasticity produced by activation of
CaMKII and LTP is demonstrated in the Science article by Hayashi et
al. below. CaMKII or LTP lead to the delivery of additional AMPA
receptors from within dendrites to receptor locations in synaptic spines.
Perhaps it is time to start a discussion about the merits of uploading
structural LTM only or structural as well as protein-morphological LTM
(such as LTP).
Driving AMPA Receptors into Synapses by LTP and CaMKII: Requirement for GluR1 and PDZ Domain Interaction Yasunori Hayashi, Song-Hai Shi, José A. Esteban, Antonella Piccini, Jean-Christophe Poncer, Roberto Malinow To elucidate mechanisms that control and execute activity-dependent synaptic plasticity, alpha -amino-3-hydroxy-5-methyl-4-isoxazole propionate receptors (AMPA-Rs) with an electrophysiological tag were expressed in rat hippocampal neurons. Long-term potentiation (LTP) or increased activity of the calcium/calmodulin-dependent protein kinase II (CaMKII) induced delivery of tagged AMPA-Rs into synapses. This effect was not diminished by mutating the CaMKII phosphorylation site on the GluR1 AMPA-R subunit, but was blocked by mutating a predicted PDZ domain interaction site. These results show that LTP and CaMKII activity drive AMPA-Rs to synapses by a mechanism that requires the association between GluR1 and a PDZ domain protein. Science, Volume 287, Number 5461 Issue of 24 Mar 2000, pp. 2262 - 2267 Abstract and Article: http://www.sciencemag.org/cgi/content/abstract/287/5461/2262 | |
| Non-destructive nanoscale X-ray imaging on silicon crystals | |
| Mon Mar 27 16:51:04 EST 2000 | jesse@bernztech.org |
|
Here is an abstract about a new technique for nondestructively peering at the nanoscale world. [Ed: rak@minduploading.org] While a non-destructive method such as this does require easily accessible slices and may not be applicable to brain tissue but possibly a mold thereof, it does allow repeated scanning and the error correction and increased precision that offers. Non-destructive determination of local strain with 100-nanometre spatial resolution S. DI FONZO, W. JARK, S. LAGOMARSINO, C. GIANNINI, L. DE CARO, A. CEDOLA & M. MÜLLER Structure sizes of ~ 180 nm are now standard in microelectronics, and state-of-the-art fabrication techniques can reduce these to just a few tens of nanometres (ref. 1). But at these length scales, the strain induced at interfaces can locally distort the crystal lattice, which may in turn affect device performance in an unpredictable way. A means of non-destructively characterizing such strain fields with high spatial resolution and sensitivity is therefore highly desirable. One approach is to use Raman spectroscopy, but this is limited by the intrinsic 0.5-µm resolution limit of visible light probes. Techniques based on electron-beam diffraction can achieve the desired nanometre-scale resolution. But either they require complex sample preparation procedures (which may alter the original strain field) or they are sensitive to distortional (but not dilational) strain within only the top few tens of nanometres of the sample surface. X-rays, on the other hand, have a much greater penetration depth, but have not hitherto achieved strain analysis with sub-micrometre resolution. Here we describe a magnifying diffraction imaging procedure for X-rays which achieves a spatial resolution of 100 nm in one dimension and a sensitivity of 10-4 for relative lattice variations. We demonstrate the suitability of this procedure for strain analysis by measuring the strain depth profiles beneath oxidized lines on silicon crystals. Nature 403, 638 - 640 (2000) © Macmillan Publishers Ltd. Abstract and Article: http://www.nature.com/cgi-taf/DynaPage.taf?file=/nature/journal/v403/n6770/abs/403638a0_fs.html | |
| Robo-monkey | |
| Mon Mar 27 16:43:53 EST 2000 | jesse@bernztech.org |
|
A recent high-profile achievement in AI research which may be of interest to those working on the software side of Whole Brain Emulation: "Thinking is robot's play" "[...] Scientists are developing machines that can learn from experience and evolve behaviour." "When it fails to grasp a rung, Robo-monkey must work out why and try again." "Swinging itself may not be a skill that is much use to 21st Century robots but the knowledge being built from this experiment will certainly lead to machines that are more interactive and self-reliant." They may also lead to a better understanding of how thinking and decision-making occurs in the human mind. Complete Story: http://news2.thls.bbc.co.uk/hi/english/sci/tech/newsid%5F628000/628270.stm | |
| Sleep deprivation reduces cortical functional response to serial subtraction | |
| Mon Mar 27 16:40:17 EST 2000 | jesse@bernztech.org |
|
Study of sleep-deprived brain functions using fMRI: Sleep deprivation-induced reduction in cortical functional response to serial subtraction Sean P. A. Drummond, Gregory G. Brown†, John L. Stricker‡, Richard B. Buxton, Eric C. Wong, J. Christian Gillin Thirteen normal volunteers were studied with fMRI during arithmetic performance after a normal night of sleep and following sleep deprivation (SD). Aims included determining whether the prefrontal cortex (PFC) and the parietal lobe arithmetic areas are vulnerable to the effects of SD. After a normal night of sleep, activation localized to the bilateral PFC, parietal lobes and premotor areas. Following SD, activity in these regions decreased markedly, especially in the PFC. Performance also dropped. Data from the serial subtraction task are consistent with Horne's PFC vulnerability hypothesis but, based on this and other studies, we suggest the localized, functional effects of SD in the brain may vary, in part, with the specific cognitive task. NeuroReport 10:3745-3748 © 1999 Lippincott Williams & Wilkins Abstract and Article: http://venus.lrponline.com/ips/template/screen.asp?J=1860&Screen_ID=15416&Menu_ID=2&SubMenu_ID= | |
| Identifying and classifying structures within the brain | |
| Wed Mar 22 13:17:26 EST 2000 | jesse@bernztech.org |
|
Recent news item on an example of identifying and classifying structures within the brain.
"Facing facts" "Viewing faces activates a small brain region called the 'fusiform face area' (FFA). An even smaller area in the right FFA is activated most strongly and consistently when presented with a face." "[...] there is no 'face' encoded in the FFA. It looks more as if its specialization is determined by the minute categorization and extensive practice that we bring to face recognition." Complete Story:http://helix.nature.com/nsu/000127/000127-5.html | |
| A neuronal analogue of state-dependant learning | |
| Wed Mar 22 13:15:57 EST 2000 | jesse@bernztech.org |
|
More memory/learning research, which may be of interest to those studying brain morphology:
A neuronal analogue of state-dependant learning D. E. Shulz, R. Sosnik, V. Ego, S. Haidarliu, E. Ahissar State-dependent learning is a phenomenon in which the retrieval of newly acquired information is possible only if the subject is in the same sensory context and physiological state as during the encoding phase. In spite of extensive behavioural and pharmacological characterization, no cellular counterpart of this phenomenon has been reported. Here we describe a neuronal analogue of state-dependent learning in which cortical neurons show an acetylcholine-dependent expression of an acetylcholine-induced functional plasticity. This was demonstrated on neurons of rat somatosensory 'barrel' cortex, whose tunings to the temporal frequency of whisker deflections were modified by cellular conditioning. Pairing whisker stimulation with acetylcholine applied iontophoretically yielded selective lasting modification of responses, the expression of which depended on the presence of exogenous acetylcholine. Administration of acetylcholine during testing revealed frequency-specific changes in response that were not expressed when tested without acetylcholine or when the muscarinic antagonist, atropine, was applied concomitantly. Our results suggest that both acquisition and recall can be controlled by the cortical release of acetylcholine. Nature (2000), Volume 403, Number 6769 Issue of 3 February 2000 Abstract:http://www.nature.com/cgi-taf/DynaPage.taf?file=/nature/journal/v403/n6769/abs/403549a0_fs.html Article: http://www.nature.com/cgi-taf/DynaPage.taf?file=/nature/journal/v403/n6769/full/403549a0_fs.html | |
| Molecular dynamics: Optical control of reactions | |
| Wed Mar 22 13:12:09 EST 2000 | jesse@bernztech.org |
|
Molecular control may prove useful to the hardware side of Whole Brain Emulation.
"Molecular dynamics: Optical control of reactions" "The fundamental time scale of chemical reactions is set by the internal vibrations of the reacting molecules, which are incredibly fast - lasting a few 10-100 femtoseconds. So short laser pulses are needed to observe or control such reactions in real time. Since the development of the femtosecond laser, the active control of molecular dynamics has greatly advanced, for example when selecting the product of a branching reaction." Complete Story:http://www.nature.com/cgi-taf/DynaPage.taf?file=/nature/journal/v403/n6769/full/403489a0_fs.html | |
| Bank of Injured Brain Tissues | |
| Sat Mar 18 12:37:01 EST 2000 | A.Koene@phys.uu.nl |
|
Brain Tissue resource for investigations into cellular and molecular
processes. Possibly also of use for those working on scanning technology.
"New Florida Bank Of Injured Brain Tissues Will Aid Nationwide Studies Of Head Injuries" "University of Florida Brain Institute researchers today announced plans to open a first-of-its-kind bank of human brain tissue to support studies of traumatic brain injuries, [...]" "The bank [...] will store samples of brain tissue from victims of brain injury and will serve as a state and national resource for the development of medical and rehabilitative therapies for patients." "William Luttle, executive director of UF's Brain Institute, said the new brain bank is ``indispensible to our efforts to figure out what happens at the cellular and molecular level, and which genes are activated at the time of brain injury and afterward''." "``To speed the process of getting this information, we plan to share the bank and to share what we learn with other scientists, health-care professionals and consumers,'' [...]"
Complete Story: http://www.sciencedaily.com/releases/2000/01/000127104025.htm | |
| Increasing the resolution of fMRI | |
| Sat Mar 18 12:07:46 EST 2000 | A.Koene@phys.uu.nl |
|
fMRI resolution limitations and a means for increaing the resolution
"Functional MRI WIll Enable Non-Invasive Visualization Of Brain" "Brain researchers throughout the world aspire to accurately map nerve cell clusters in action, [...]" "Yet, until now they have been unable to do so directly, and have had to rely on several indirect methods such as PET, optical imaging and fMRI. Brain-Vein Mapping" "Using fMRI, scientists trach changes in the levels of oxygen bound to hemoglobin in the blood steam, resulting from hemoglobin supplying oxygen to active nerve cells." "Until recently, the level of mapping accuracy rendered by the techniques was fairly limited: they could map an active area in the human at an accuracy level of 1-3mm (fMRI) or 3-7mm (PET), and thus were unable to map the brain's basic processing units - the 0.5mm wide microprocessors" "Two months ago, Ivo Vanzetta and Amiram Grinvald of the Weizmann Institute of Science, published a paper in Science in which they proposed how the fMRI system's resolution could be greatly enhanced. A team of scientists from the University of Minnesota, led by Prof. Kamil Ugurbil, has adopted this recipe. [...]" "[...]Dae-Shik Kim, Timothy Duong, and Seong-Gi Kim from the Minnesota group report in Nature Neuroscience [...] that the exact location of firing indeed corresponds to the location of the initial dip [a negative signal that appears earlier then the ``activity crest'' commonly detected by MRI wich appears roughly 6 seconds after the onset of electrical activity]" "The current Nature Neuroscience contains a News and Views article written by Amiram Grinvald, Hamutal Slovin and Ivo Vanzetta of the Weizmann Institute, in which they discuss the accomplishment achieved by the Minnesota team, and provide new data from optical imaging. Taken together, these articles suggest that by focusing on the initial dip, fMRI will enable non-invasive mapping of cortical columns [...]" Complete Story: http://www.sciencedaily.com/releases/2000/01/000131080735.htm | |
| The Undiscovered Mind | |
| Sat Feb 12 13:59:27 EST 2000 | rak@minduploading.org |
|
A perspective on the state of neuroscience and cognitive science after
the 1990's, designated the "Decade of the Brain" by the U.S. Congress.
Appearing in HMS
Beagle, an essay about The Undiscovered Mind: How the Human
Brain Defies Replication, Medication, and Explanation by John
Horgen.
"The Undiscovered Mind" "By avoiding emotion, neuroscientists and cognitive scientists have created a peculiarly one-dimensional picture of the mind [...]" "``[...] minds without emotions are not really minds at all. They are souls on ice - cold, lifeless creatures devoid of any desires, fears, sorrows, pains, or pleasures.''" "Psychologists once believed that the subjective sensation of fear is the first component of the fear response; increased heart rate, sweating, and other physiological symptoms were thought to be triggered by the subjective sensation. LeDoux contended that the opposite is probably true; physiological symptoms occur first and then initiate the subjective sensation of fear. In many cases, moreover, the fear response might never generate a conscious sensation. Our conscious, subjective feelings ``are red herrings, detours, in the scientific study of emotions,'' LeDoux has written." "LeDoux felt that too much attention had been paid to consciousness lately. ``It would surely get you the Nobel Prize if you figured it out,'' he told me, ``but I don't think it would tell us what we need to know'' about the mind. Although consciousness is often equated with the mind, most mental processes occur beneath the level of awareness, LeDoux pointed out. Consciousness, moreover, is a relatively recent innovation of evolution. ``Basically the brain is unconscious. Somewhere in evolution consciousness evolved as a module. It's connected up to some other parts of the brain, but not the rest of it.''" "Explaining consciousness is not as important as understanding how the brain draws on both genes and experience to create a self, a personal identity, in each individual. ``That to me is the big question: how our brain makes us who we are. Explaining consciousness wouldn't explain that.'' The key to this issue is understanding how both nature and nurture affect the brain's wiring. ``What's often overlooked is that nature and nurture speak the same language, which is the synaptic language,'' LeDoux said. Ultimately all influences on personality, genetic or experiential, become manifest at the level of the connections between neurons." "Then LeDoux suggested that neuroscience might not need a unifying theory: Maybe what we need most are lots of little theories." "The field of neuroscience is in a position to make progress on these problems, even if it doesn't come up with a theory of mind and brain." Complete Story: http://www.biomednet.com/hmsbeagle/71/xcursion/essay | |
| Quantum mirage may enable atom-scale circuits | |
| Mon Feb 7 19:04:22 EST 2000 | rak@minduploading.org |
|
Playing with atoms and quantum properties... hmm... sounds like my
childhood reveries about a Matter-Data-Processing-System were pretty
good predictions, although for now we'll have to settle for
``quantum-mirage'' information transport. In any case, all manipulations
of matter at that level are incredibly promising to the hardware side of
whole brain emulation.
"``Quantum mirage'' may enable atom-scale circuits" "SAN JOSE, Calif. (February 3, 2000) -- IBM scientists have discovered a way to transport information on the atomic scale that uses the wave nature of electrons instead of conventional wiring. The new phenomenon, called the "quantum mirage" effect, may enable data transfer within future nanoscale electronic circuits too small to use wires." "``This is a fundamentally new way of guiding information through a solid,'' said IBM Fellow Donald M. Eigler, IBM's lead researcher on this project.. ``We call it a mirage because we project information about one atom to another spot where there is no atom.''" "To create the quantum mirage, the scientists first moved several dozen cobalt atoms on a copper surface into an ellipse-shaped ring. As Michael Crommie (who is now a professor at the University of California-Berkeley), Lutz and Eigler had shown in 1993, the ring atoms acted as a ``quantum corral'' -- reflecting the copper's surface electrons within the ring into a wave pattern predicted by quantum mechanics." "``The quantum mirage technique permits us to do some very interesting scientific experiments such as remotely probing atoms and molecules, studying the origins of magnetism at the atomic level, and ultimately manipulating individual electron or nuclear spins,'' said Dr. Manoharan." Complete Story: http://www.almaden.ibm.com/almaden/media/mirage.html | |
| Confocal microscopic estimation of GABAergic nerve terminals in the central nervous system | |
| Mon Feb 7 12:25:46 EST 2000 | rak@minduploading.org |
|
This procedure can be of great interest to those of us investigating
how best to extract morphological data from the brain, discussing
both estimation techniques and the correlation between form and
function through confocal microscopy.
Confocal microscopic estimation of GABAergic nerve terminals in the central nervous system J.J. Hiscock, S. Murphy and J.O. Willoughby We describe a method for estimating the average proportion of GABAergic terminal area relative to total nerve terminal area with confocal microscopy. Nerve terminal regions were identified with dual colour immunofluorescence on Vibratome sections with an antibody to synaptophysin (SYN), and GABAergic processes, including axon terminals, were identified with an antibody to glutamic acid decarboxylase (GAD). Sections were viewed in an Olympus AX70 microscope attached to a Biorad 1024 MRC scanning confocal system. Images were collected with a 100× objective from the same tissue locations and imported into the NIH-Image program, where black and white binary images were obtained for co-localisation and quantitation. Measurements were made separately of areas of SYN/GAD (GABAergic terminals) and SYN labelling (all terminals). The relative proportion of GABAergic terminal areas in visual cortex (6.1±1%; mean±SE), CA1 hippocampus (2.6±0.5%) and deep cerebellar nuclei (46.6±3%) are consistent with what is known of the relative levels of inhibitory input to these structures. The assumptions that SYN labelling is restricted to axon terminals, and that SYN labels all axon terminals was tested by ultrastructural localisation of SYN in the three brain regions examined. Only 7.4+0.4% of SYN-labelled profiles could not be positively identified as synaptic vesicle-containing axon terminals, and between 93.4 and 99.2% of vesiculated axon profiles were SYN-positive. These results suggest that SYN is a very reliable marker for axon terminals, and validates the confocal analytical approach. The confocal method allows rapid sampling of many brain regions and would be suitable for examining terminals containing any neurotransmitter that can be detected immunocytochemically. Journal of Neuroscience Methods (2000), Volume 95:1, pages 1-11 Abstract and Article: http://ir.library.uu.nl/cgi-bin/muscat/els?db=elsevier&x=art&r=375367 | |
| Contacts and Members Page | |
| Tue Feb 1 11:01:35 EST 2000 | rak@minduploading.org |
| There is now a page for contact numbers, email and addresses, as well as active MURG member profiles: minduploading.org/murg-members.html. | |
| The Prospect of Mind Uploading (draft) | |
| Tue Feb 1 00:06:35 EST 2000 | rak@minduploading.org |
| The article by Graham Hearn, ``The Prospect of Mind Uploading'', currently under review at Open Scientific Publications, which also made several appearances on the MURG list, is now available in a draft version at the Articles page: minduploading.org/mu-articles.html. | |
| Hundreds of Scientists Sign Biotechnology Declaration | |
| Sat Jan 29 10:19:41 EST 2000 | rak@minduploading.org |
|
Many thanks to Graham Hearn for alerting us to this one.
A group of scientists are trying to set the record straight, countering popular paranoia and misinformation about biotechnology. This may be significant for us, since mind uploading could well be classified as very invasive biotechnology. "Hundreds of Scientists Sign Biotechnology Declaration" "January 22, 2000 - Montreal - A declaration supporting agricultural biotechnology and signed by over 600 scientists from around the world was released today at a press briefing in Montreal. The briefing, sponsored by International Consumers for Civil Society, featured Dr. C. S. Prakash, Director of the Center for Plant Biotechnology Research at Tuskegee University, the author of the proclamation." "The declaration declares that ``recombinant DNA techniques constitute powerful and safe means for the modification of organisms and can contribute substantially in enhancing quality of life by improving agriculture, health care, and the environment.''" Complete Story: http://www.consumeralert.org/press/012200petition.html | |
| Professor Cyborg | |
| Sat Jan 29 10:14:14 EST 2000 | rak@minduploading.org |
|
Many thanks to Graham Hearn for pointing us to this one.
Perhaps Kevin Warwick is somewhat of a sensationalist, but if his chip works and he can store large continuous streams of data through his chip implant, then that information can be a boon to mind uploading and all of neuroscience. "Professor Cyborg" "[Warwick] is planning to hard-wire his brain directly to his computer." "So far, Warwick's most notorious robotic accomplishment occurred last year, when one of his fleet was the first robot to autonomously train another robot." "In 18 months, Warwick will again undergo surgery, this time receiving not just a transponder implant in his arm but a connection to his nervous core -- a tiny collar that encircles the bundle of nerve fibers at the top of his arm, reading the signals from his nervous system and transmitting those to his computer. Of course, just how his nervous signals will translate into computer commands remains to be seen -- much of the experiment will involve testing to see if he can turn on lights on his computer by waving his arm in certain ways." "This implant will not merely send signals to his computer, however; it will also receive them. The computer should be able to record and store sets of Warwick's nervous signals and transmit them back at a later time; if all goes well, he'll be able to ``play back'' the motion of flexing his elbow or wiggling his fingers. He could even ``re-experience'' the nervous signals related to his emotions, ``playing back'' the signals his nervous core sent when he was feeling happy or stressed. ``Will I feel the emotion I felt before, will I feel a different one, will it be better or will it be worse? We have no idea,'' he speculates. ``The big worry is that while we'll be able to see what those transmissions will do to my fingers, they will also go back to the brain. What will my brain will of those signals? That's a smidgen dangerous. But it's extremely exciting.''" "In the most bizarre touch of all, Warwick's wife has agreed to receive an identical implant. The two human lab rats, he hopes, should be capable of transmitting signals from nervous system to nervous system. Conceivably, Warwick's feelings of anger or amorousness could be transmitted to her, and vice versa [...]" Complete Story: http://www.salon.com/tech/feature/1999/10/20/cyborg/ | |
| Scientists Create RNA Computer | |
| Fri Jan 28 13:20:17 EST 2000 | rak@minduploading.org |
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Only a short while ago, we received news of the storage capacity in dna computing (see MU News of Fri Jan 21 10:51:38 EST 2000). Now they've gone ahead and solved an actual (computationally intensive) puzzle with strands of RNA. The results may not seem mind-boggling when compared with silicon computations... yet, but it certainly seems to have a future in highly parallel applications. As it works well in tial-and-error computations, it would seem highly suited to both brute-force decryption and cellular automata. The latter can be very useful for component reconstruction and error correction in Whole Brain Emulation.
"Scientists Create RNA Computer" "Princeton University researchers have developed a kind of computer that uses the biological molecule RNA to solve complex problems." "In work to be published in the Proceedings of the National Academy of Sciences, the Princeton scientists used a test tube containing 1,024 different strands of RNA to solve a simple version of the "knight problem," a chess puzzle that is representative of a class of problems that requires brute-force computing. The knight problem asks how many and where can one place knights on a chessboard so they can not attack each other. For the purposes of their experiment, the researchers restricted the board to just nine squares, so there were 512 possible combinations. Of these, the RNA computer correctly identified 43 solutions." "It also produced one incorrect response, highlighting the need to develop error-checking techniques in chemical computing." "[...] with vast numbers of genetic fragments floating in a test tube, a biomolecular computer could perform thousands or millions of calculations at the same time." "For example, in the knight problem, each strand of RNA represented a possible] solution, but the researchers did not need to sort through each one individually; in a series of five steps, a specially targeted enzyme slashed away all the strands that did not match the requirements of a correct solution. Researchers believe that such techniques could be valuable for problems that need to be solved by trial and error, where it is cumbersome to test possible solutions one at a time." "[...] words written in the letters of DNA, referred to as A, T, C and G, could represent the ones and zeroes used in computer logic. Computing is accomplished by eliminating molecules whose sequences appear to be poor solutions and retaining ones that seem more promising" "Landweber found that substituting RNA for DNA gave her more flexibility in developing a computing system. [...] With RNA, Landweber's group could use just one universal enzyme that targets any part of the molecule. This aspect streamlines their approach and makes it inherently 'scalable' to larger problems." Complete Story: http://www.princeton.edu/pr/news/00/q1/0114-rna.htm | |
| Scientists re-grow damaged nerves | |
| Fri Jan 28 11:58:36 EST 2000 | rak@minduploading.org |
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Regrowth of severed nerves. This has implications not only for spinal injuries, but also for those seeking reanimation following cryonic suspension. The processes involved when nerves reconnect with the intention of restoring correct functioning can also teach us something about the implications of (and possible means of correcting) errors in the uploading process, especially those due to missing data at the edges of scans.
"Scientists re-grow damaged nerves" "The project, led by researchers at St Thomas' Hospital in London, UK, managed to induce the nerves to grow back and join into the spinal cord." "The team used the right combination of "neurotrophic factors" - proteins which encourage natural nerve growth." "[John Kavanagh] said that although this breakthrough applied directly to ``peripheral'' nerve damage rather than spinal cord injuries themselves, there was no reason why it could not in theory apply to nerve re-growth in any part of the body." Complete Story: http://http://news2.thls.bbc.co.uk/hi/english/health/newsid%5F610000/610528.stm | |
| Nogo-A, an inhibitor of neurite outgrowth | |
| Fri Jan 28 11:35:40 EST 2000 | rak@minduploading.org |
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Two interesting articles on Nogo-A, a neuite outgrowth inhibitor. Since this is tied in with the whole topic if neurogenesis and synaptogenesis, the findings are of potential interest to those of us researching the dynamic (and memory) models necessary for Whole Brain Emulation.
Nogo-A is a myelin-associated neurite outgrowth inhibitor and an antigen for monoclonal antibody IN-1 MAIO S. CHEN, ANDREA B. HUBER, MARJAN E. VAN DER HAAR, MARCUS FRANK, LISA SCHNELL, ADRIAN A. SPILLMANN, FRANZISKA CHRIST & MARTIN E. SCHWAB The capacity of the adult brain and spinal cord to repair lesions by axonal regeneration or compensatory fibre growth is extremely limited. A monoclonal antibody (IN-1) raised against NI-220/250, a myelin protein that is a potent inhibitor of neurite growth, promoted axonal regeneration and compensatory plasticity following lesions of the central nervous system (CNS) in adult rats. Here we report the cloning of nogo A, the rat complementary DNA encoding NI-220/250. The nogo gene encodes at least three major protein products (Nogo-A, -B and -C). Recombinant Nogo-A is recognized by monoclonal antibody IN-1, and it inhibits neurite outgrowth from dorsal root ganglia and spreading of 3T3 fibroblasts in an IN-1-sensitive manner. Antibodies against Nogo-A stain CNS myelin and oligodendrocytes and allow dorsal root ganglion neurites to grow on CNS myelin and into optic nerve explants. These data show that Nogo-A is a potent inhibitor of neurite growth and an IN-1 antigen produced by oligodendrocytes, and may allow the generation of new reagents to enhance CNS regeneration and plasticity. Nature (2000) 403, 434 - 439 Abstract and Article: http://www.nature.com/server-java/Propub/nature/403434A0.abs_frameset?context=toc Identification of the Nogo inhibitor of axon regeneration as a Reticulon protein TADZIA GRANDPRÉ, FUMIO NAKAMURA, TIMOTHY VARTANIAN & STEPHEN M. STRITTMATTER Adult mammalian axon regeneration is generally successful in the peripheral nervous system (PNS) but is dismally poor in the central nervous system (CNS). However, many classes of CNS axons can extend for long distances in peripheral nerve grafts. A comparison of myelin from the CNS and the PNS has revealed that CNS white matter is selectively inhibitory for axonal outgrowth. Several components of CNS white matter, NI35, NI250(Nogo) and MAG, that have inhibitory activity for axon extension have been described. The IN-1 antibody, which recognizes NI35 and NI250(Nogo), allows moderate degrees of axonal regeneration and functional recovery after spinal cord injury. Here we identify Nogo as a member of the Reticulon family, Reticulon 4-A. Nogo is expressed by oligodendrocytes but not by Schwann cells, and associates primarily with the endoplasmic reticulum. A 66-residue lumenal/extracellular domain inhibits axonal extension and collapses dorsal root ganglion growth cones. In contrast to Nogo, Reticulon 1 and 3 are not expressed by oligodendrocytes, and the 66-residue lumenal/extracellular domains from Reticulon 1, 2 and 3 do not inhibit axonal regeneration. These data provide a molecular basis to assess the contribution of Nogo to the failure of axonal regeneration in the adult CNS. Nature (2000), 403, 439 - 444 Abstract and Article: http://www.nature.com/server-java/Propub/nature/403439A0.abs_frameset?context=toc | |
| Complementary Neural Mechanisms for Tracking Items in Human Working Memory | |
| Fri Jan 28 10:33:34 EST 2000 | rak@minduploading.org |
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This article is interesting to those of us researching Working or Short Term memory, and is topically relevant considering the recent MURG post by Eugene ("The Dynamics of Brain Processing"), and its emphasis on the recurrent effects of internal brain states (e.g. attention) on sensory neuronal systems.
Complementary Neural Mechanisms for Tracking Items in Human Working Memory Yang Jiang, James V. Haxby, Alex Martin, Leslie G. Ungerleider, Raja Parasuraman Recognition of a specific visual target among equally familiar distracters requires neural mechanisms for tracking items in working memory. Event-related functional magnetic resonance imaging revealed evidence for two such mechanisms: (i) Enhanced neural responses, primarily in the frontal cortex, were associated with the target and were maintained across repetitions of the target. (ii) Reduced responses, primarily in the extrastriate visual cortex, were associated with stimulus repetition, regardless of whether the stimulus was a target or a distracter. These complementary neural mechanisms track the status of familiar items in working memory, allowing for the efficient recognition of a currently relevant object and rejection of irrelevant distracters. Science (2000), Volume 287, Number 5453 Issue of 28 Jan 2000, pp. 643 - 646 Abstract and Article: http://www.sciencemag.org/cgi/content/abstract/287/5453/643 | |
| Nanotube Molecular Wires as Chemical Sensors | |
| Fri Jan 28 09:51:58 EST 2000 | rak@minduploading.org |
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This article investigates some very promising new sensors at the molecular level. It is not difficult to see where they might be extremely valuable as tools in the data extraction stage of mind uploading.
Nanotube Molecular Wires as Chemical Sensors Jing Kong, Nathan R. Franklin, Chongwu Zhou, Michael G. Chapline, Shu Peng, Kyeongjae Cho, Hongjie Dai Chemical sensors based on individual single-walled carbon nanotubes (SWNTs) are demonstrated. Upon exposure to gaseous molecules such as NO2 or NH3, the electrical resistance of a semiconducting SWNT is found to dramatically increase or decrease. This serves as the basis for nanotube molecular sensors. The nanotube sensors exhibit a fast response and a substantially higher sensitivity than that of existing solid-state sensors at room temperature. Sensor reversibility is achieved by slow recovery under ambient conditions or by heating to high temperatures. The interactions between molecular species and SWNTs and the mechanisms of molecular sensing with nanotube molecular wires are investigated. Science (200), Volume 287, Number 5453 Issue of 28 Jan 2000, pp. 622 - 625 Abstract and Article: http://www.sciencemag.org/cgi/content/abstract/287/5453/622 | |
| Mind uploading makes an appearance on slashdot.org | |
| Wed Jan 26 22:58:35 EST 2000 | rak@minduploading.org |
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Well, it has finally happened... thanks to Kurzweil, mind uploading has appeared on slashdot.org. Now if they discover our web pages, we will most certainly experience the (in)famous slashdot effect. Quick, find something to hold on to. ;)
"Science: Putting Your Brain into A Computer" "``There is an article in the newest Psychology Today (and on their Web page) that talks about uploading the human brain into a computer within the next 50 years. Essentially this would mean immortality through virtual clones. Their description of how that the scanning of synapses and neurons would be done is really detailed and interesting.'' Excellent article - and written by Ray Kurzweil, the author of The Age of Spiritual Machines, one of the more well-written texts on the growth of intelligence in computers." Complete Story: http://slashdot.org/article.pl?sid=00/01/26/1133249&mode=nested | |
| Scientists report advance in DNA computing | |
| Fri Jan 21 10:51:38 EST 2000 | rak@minduploading.org |
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An alternative approach to powerful computing with some serious storage capacity.
Scientists report advance in DNA computing "Scientists have taken DNA computing from the free-floating world of the test tube and anchored it securely to a surface of glass and gold. In so doing, they have taken a small but important step forward in the quest to harness the vast potential of DNA to perform the same tasks that now require silicon and miniature electronic circuits." "DNA computing is a nascent technology that seeks to capitalize on the enormous informational capacity of DNA, biological molecules that can store huge amounts of information and are able to perform operations similar to a computer's through the deployment of enzymes, biological catalysts that act like software to execute desired operations." "The appeal of DNA computing lies in the fact that DNA molecules can store far more information than any existing conventional computer chip. It has been estimated that a gram of dried DNA can hold as much information as a trillion CDs. Moreover, in a biochemical reaction taking place in a tiny surface area, hundreds of trillions of DNA molecules can operate in concert, creating a parallel processing system that mimics the ability of the most powerful supercomputer." Complete Story: http://www.news.wisc.edu/thisweek/view.msql?id=3542 | |
| Enhanced: Quantum Information Processing Without Entanglement | |
| Fri Jan 21 10:18:19 EST 2000 | rak@minduploading.org |
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Peter Knight takes a broader, descriptive look at Quantum Computing, with references to the preceding article by Ahn et al.
Enhanced: Quantum Information Processing Without Entanglement Peter Knight Quantum computers have the potential to significantly reduce the amount of time required for certain computational tasks. It is often assumed that for a quantum computer to be efficient, entanglement between different states is required. Ahn et al. (page 463) show that a single quantum system possessing no entanglement whatsoever can implement the search algorithm in a non-classical and highly effective way. Science (2000), Volume 287, Number 5452 Issue of 21 Feb 2000, pp. 441 - 442 Abstract and Article: http://www.sciencemag.org/cgi/content/summary/287/5452/441 | |
| Information Storage and Retrieval Through Quantum Phase | |
| Fri Jan 21 10:00:05 EST 2000 | rak@minduploading.org |
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A clear little piece about storage and retrieval using quantum states, promising and certainly useful to mind uploading.
Information Storage and Retrieval Through Quantum Phase J. Ahn, T. C. Weinacht, P. H. Bucksbaum Information was stored as quantum phase in an N-state Rydberg atom data register. One or more flipped states stored in an eight-state atomic wave packet could be retrieved in a single operation, in agreement with a recent proposal by Grover. Science (2000), Volume 287, Number 5452 Issue of 21 Jan 2000, pp. 463 - 465 Abstract and Article: http://www.sciencemag.org/cgi/content/abstract/287/5452/463 | |
| Brain interfacing, artificial vision | |
| Mon Jan 17 00:50:27 EST 2000 | rak@minduploading.org |
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Wow, brain interfacing! The obvious first target, the visual system.
"New hope for artificial sight: Blind man `sees' objects with camera wired to brain" "NEW YORK, Jan. 16 - A blind man can read large letters and navigate around big objects by using a tiny camera wired directly to his brain, the first artificial eye to provide useful vision, a researcher reports." "[...] He perceives up to 100 specks of light that appear and disappear, like stars that come and go behind passing clouds, as his field of vision shifts." "He volunteered for the study and got the brain implant in 1978; scientists have been working since then to improve the software." "It's the first demonstration of useful artificial vision [...]" Complete Story: http://www.msnbc.com/news/358275.asp | |
| Three articles in Science on Inhibition and Interneurons | |
| Sun Jan 16 12:39:56 EST 2000 | rak@minduploading.org |
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Three articles on Inhibition and Interneurons in Science (2000), vol.278:5451.
Organizing Principles for a Diversity of GABAergic Interneurons and Synapses in the Neocortex Anirudh Gupta, Yun Wang, Henry Markram A puzzling feature of the neocortex is the rich array of inhibitory interneurons. Multiple neuron recordings revealed numerous electrophysiological-anatomical subclasses of neocortical gamma-aminobutyric acid-ergic (GABAergic) interneurons and three types of GABAergic synapses. The type of synapse used by each interneuron to influence its neighbors follows three functional organizing principles. These principles suggest that inhibitory synapses could shape the impact of different interneurons according to their specific spatiotemporal patterns of activity and that GABAergic interneuron and synapse diversity may enable combinatorial inhibitory effects in the neocortex. Science, Volume 287, Number 5451 Issue of 14 Jan 2000, pp. 273 - 278 Abstract and Article: http://www.sciencemag.org/cgi/content/abstract/287/5451/273 Distal Initiation and Active Propagation of Action Potentials in Interneuron Dendrites Marco Martina, Imre Vida, Peter Jonas Fast and reliable activation of inhibitory interneurons is critical for the stability of cortical neuronal networks. Active conductances in dendrites may facilitate interneuron activation, but direct experimental evidence was unavailable. Patch-clamp recordings from dendrites of hippocampal oriens-alveus interneurons revealed high densities of voltage-gated sodium and potassium ion channels. Simultaneous recordings from dendrites and somata suggested that action potential initiation occurs preferentially in the axon with long threshold stimuli, but can be shifted to somatodendritic sites when brief stimuli are applied. After initiation, action potentials propagate over the somatodendritic domain with constant amplitude, high velocity, and reliability, even during high-frequency trains. Science, Volume 287, Number 5451 Issue of 14 Jan 2000, pp. 295 - 300 Abstract and Article: http://www.sciencemag.org/cgi/content/abstract/287/5451/295 Diversity in Inhibition Richard Miles The seamless balance between inhibitory and excitatory nerve cells is necessary for the correct functioning of the brain. In a Perspective, Miles discusses a series of new findings (Martina et al.; Gupta et al.) that enable inhibitory neurons to be classified into three groups and characterized according to their properties. Science, Volume 287, Number 5451 Issue of 14 Jan 2000, pp. 244 - 246 Abstract and Article: http://www.sciencemag.org/cgi/content/summary/287/5451/244 | |
| HAVE A GREAT NEW YEAR AND AN AMAZING NEW MILLENIUM | |
| Sat Jan 1 00:22:46 EST 2000 | rak@minduploading.org |
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HAVE A GREAT NEW YEAR AND AN AMAZING NEW MILLENIUM!!!
Best wishes for a fabulous New Year and New Millenium to everyone on MURG! Let's mark the beginning of many great strides toward mind uploading this year, opening up the millenium and beyond to all of us! I'm celebrating in Ottawa right now, and I hope all of you are having a wonderful quiet or festive New Year!
All the best to a great bunch of people, | |
| Scientists map brain's primary memory network | |
| Thu Dec 16 12:02:10 EST 1999 | Eugene Leitl |
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Researchers have mapped a short-term memory encoding process in the dorsal hippocampus.
"Scientists map brain's primary memory network"
"Contact: Robert Conn (Rconn@wfubmc.edu), Mark Wright (Mwright@wfubmc.edu) or Jim Steele (Jsteele@wfubmc.edu) "...a team of Wake Forest University investigators has mapped the functional organization of the hippocampus, the brain's primary memory network, a step that other scientists are calling ``a major breakthrough.'' . The researchers - Sam A, Deadwyler, Ph.D., Robert E. Hampson, Ph.D. and John D. Simeral - report in today's (Dec. 9) Nature that they have mapped the way that a part of the brain, the dorsal hippocampus, encodes information when rats perform a short-term memory task." Complete Story: http://www.eurekalert.org/releases/wfbu-smb120699.html | |
| More Synapses Seen In Brains Of Intellectually Skilled | |
| Thu Dec 16 12:01:57 EST 1999 | Eugene Leitl |
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Discovery of skill-related synaptic densities.
"More Synapses Seen In Brains Of Intellectually Skilled" "Education not only makes a person smarter, it may generate a specific type of synapse in the prefrontal cortex of the brain, Illinois and Russian neuroscientists say." "``There clearly were more synapses found in subjects with intellectually skilled professions, such as engineering or teaching,'' said James E. Black, who is part of a team examining post-mortem brain tissue at the University of Illinois Beckman Institute for Advanced Science and Technology." Complete Story: http://unisci.com/stories/19994/1129992.htm | |
| Scientists Discover How to Make Nanostructures Assemble Themselves | |
| Thu Dec 16 12:01:43 EST 1999 | rak@minduploading.org |
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Lithographically induced self-assembly of nanostructures.
"Scientists Discover How to Make Nanostructures Assemble Themselves: Technique Could Yield New Generation of Miniature Electronics" "Contact: Steven Schultz (609) 258-5729" "Princeton researchers have created ultrasmall plastic structures with a method that is cheaper and more versatile than previous techniques. The discovery has yielded surprising insights into the behavior of materials at very small scales..." "Professor of electrical engineering Stephen Chou and graduate student Larry Zhuang found that they could coax a flat sheet of plastic resin to assemble itself into a minute, perfectly ordered array of pillars -- with remarkably little specialized equipment. The pillars are a little more than half a micron (a millionth of a meter) in height and width..." "...[Chou] dubbed the new approach LISA, for Lithographically Induced Self Assembly..." "...LISA could solve the increasingly difficult problem of attaching wires to ever-shrinking electronic devices. ``Using the LISA process, you can fabricate your wires first, then it will assemble your devices between the wires on its own,'' says Chou..." "Chou also believes LISA could be valuable to biophysicists at Princeton and elsewhere, who have found that passing DNA strands through a minute array of posts provides a cheap and simple way of sorting the molecules by size." "Please Note: Pictures are available at: www.princeton.edu/pr/pictures/other/LISA/" Complete Story: http://www.princeton.edu/pr/news/99/q4/1118-chou.htm | |
| Yale Research on Molecular Switches May Lead to Smaller, Cheaper Computers | |
| Thu Dec 16 12:01:02 EST 1999 | rak@minduploading.org |
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Self-assembly of molecular-size electronic switches for computational devices.
"Yale Research on Molecular Switches May Lead to Smaller, Cheaper Computers" "Yale and Rice University scientists have demonstrated molecular devices that act as reversible electronic switches, making it possible to build smaller computers that are less expensive." "...the Yale research team has identified a reversible electronic switch that is the size of a single molecule." "...Harold Hodgkinson Professor of Engineering and Applied Science and chair of electrical engineering at Yale. ``We also did it using a fabrication method which has the potential to radically reduce the cost of future microcircuits.''" "...the researchers also used a fabrication method called ``self assembly'', where the device actually self-forms..." Complete Story: http://www.yale.edu/opa/newsr/99-11-18-01.all.html | |
| Neuroscience: Cultured Neural Networks | |
| Thu Dec 16 11:15:23 EST 1999 | Eugene Leitl |
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From a post by Larry Price to the Transhuman Mailing List: The use of simulated environments to stimulate nerve cultures in vitro, allowing real-time study.
The article `` | |