[MURG] [>Htech] sciencedaily: mice with neurons that glow when activated used to map whisker neuron activation (fwd from alito@organicrobot.com)

Wed Jul 14 13:22:57 EST 2004

----- Forwarded message from Alejandro Dubrovsky <alito at organicrobot.com> -----

From: Alejandro Dubrovsky <alito at organicrobot.com>
Date: Thu, 15 Jul 2004 04:33:43 +1000
To: transhumantech <transhumantech at yahoogroups.com>
Subject: [>Htech] sciencedaily: mice with neurons that glow when activated used to
	map whisker neuron activation
X-Mailer: Evolution 1.5.90 
Reply-To: transhumantech at yahoogroups.com

(
http://www.sciencedaily.com/releases/2004/07/040714085553.htm
)

Carnegie Mellon Neuroscientist Develops Tool To Image Brain Function At
The Cellular Level
PITTSBURGH -- Carnegie Mellon University neuroscientist Alison Barth has
developed the first tool to identify and study individual neurons
activated in a living animal. This advance, described in the July 21
issue of The Journal of Neuroscience, ultimately could lead to the
development of targeted drugs that directly affect specific neurons
involved in neurological diseases that alter behavior, learning and
perception.

While neuroscientists have made great strides in identifying the general
areas of the brain that perform certain tasks, these methods have worked
at the gross level and with poor resolution, according to Barth, an
assistant professor of biological sciences at the university's Mellon
College of Science. To overcome these limitations, Barth created a
transgenic mouse that couples the green fluorescent protein (GFP) with
the gene c-fos, which turns on when nerve cells are activated. Using
this method, researchers can see specific neurons glow as they are
activated by external stimuli such as sensory experience or drug
treatment. 

"Our transgenic mouse is a novel tool that can be used to visualize, in
living brain tissue, a single neuron that has been activated in response
to an animal's experience," Barth said. 

Barth used the fosGFP mice to identify neurons that are activated during
a specific rearing condition ? experiencing the world through one
whisker. By locating a cluster of glowing neurons, she was able to
precisely identify the area of the brain involved in processing sensory
input from the single whisker. Once the neurons of interest had been
located, Barth then examined each neuron to determine how its
electrophysiological and synaptic properties changed in response to
sensory input. Her results are the first to show alterations in the rate
at which neurons transmit electrical signals after increased sensory
input in vivo. 

Barth's technology is based on the decades-long understanding that a
neuron must turn on new genes to firmly encode memories in the brain.
Each time c-fos is activated in Barth's transgenic mouse, so is GFP. The
result is an animal whose neurons literally glow when they are activated
by stimuli. 

"The fosGFP mice offer better access than ever before to the specific
neurons that have been activated by an animal's experience," Barth
said. 

Although scientists can detect c-fos expression using another technique,
it requires disrupting membranes and disturbing connections between
nerve cells. Barth's method circumvents these drawbacks, allowing
scientists to study living neurons at the cellular level. 

Using the fosGFP mouse to identify a discrete area of the brain involved
in inputting sensory information from a single whisker, Barth found that
the electrical properties of neurons in the area stimulated by sensation
were different than those of neurons deprived of sensation.
Specifically, she discovered that neurons in the sensory-stimulated area
underwent changes that made them less likely to send a signal to
surrounding neurons. 

"These changes are hypothesized to be part of a dynamic interplay
between forces that maintain neural firing within an optimal range and
those that strengthen particular connections between cells, thought to
underlie learning," Barth said. 

The fosGFP mouse is a broadly applicable tool for many neuroscientists,
according to Barth, who has patented the mouse and licensed it
commercially. 

The fosGFP mouse should help scientists see which neurons are active in
different neurological diseases and has broad implications for rational
drug design in the treatment of schizophrenia as well as many other
psychiatric diseases, according to Barth. For instance, the drug
Clozapine, which is used to treat schizophrenia, is effective at
relieving symptoms associated with the disease, but it isn't clear which
part of the brain or which specific neurotransmitter receptors are being
affected by the drug. Using the fosGFP mouse to study Clozapine's
mechanism of action may provide a better understanding not only of which
neurons are activated by the drug, but also how they change on continued
exposure to the drug. 

###

The Mellon College of Science at Carnegie Mellon University maintains
innovative research and educational programs in biological sciences,
chemistry, physics, mathematics and several interdisciplinary areas. For
more information, visit http://www.cmu.edu/mcs.

________________________________________________________________________

This story has been adapted from a news release issued by Carnegie
Mellon University.

------------------------ Yahoo! Groups Sponsor --------------------~--> 
Make a clean sweep of pop-up ads. Yahoo! Companion Toolbar.
Now with Pop-Up Blocker. Get it for free!
http://us.click.yahoo.com/L5YrjA/eSIIAA/yQLSAA/PMYolB/TM
--------------------------------------------------------------------~-> 

-----BEGIN TRANSHUMANTECH SIGNATURE-----
Post message: transhumantech at yahoogroups.com
Subscribe:    transhumantech-subscribe at yahoogroups.com
Unsubscribe:  transhumantech-unsubscribe at yahoogroups.com
List owner:   transhumantech-owner at yahoogroups.com
List home:    http://www.yahoogroups.com/group/transhumantech/
-----END TRANSHUMANTECH SIGNATURE----- 
Yahoo! Groups Links

<*> To visit your group on the web, go to:
    http://groups.yahoo.com/group/transhumantech/

<*> To unsubscribe from this group, send an email to:
    transhumantech-unsubscribe at yahoogroups.com

<*> Your use of Yahoo! Groups is subject to:
    http://docs.yahoo.com/info/terms/

----- End forwarded message -----
-- 
Eugen* Leitl <a href="http://leitl.org">leitl</a>
______________________________________________________________
ICBM: 48.07078, 11.61144            http://www.leitl.org
8B29F6BE: 099D 78BA 2FD3 B014 B08A  7779 75B0 2443 8B29 F6BE
http://moleculardevices.org         http://nanomachines.net
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/pgp-signature
Size: 198 bytes
Desc: not available
Url : http://askja.bu.edu/pipermail/murg/attachments/20040714/40b69bf4/attachment.pgp