[MURG] Non-invasive 3-D Scanning

[Joseph J. Strout]

At 3:13 PM -0500 12/15/03, Yan King Yin wrote:

>We need:
>
>1) structural information
>
>2) synaptic strength -- the size of a synapse is quite
>    stable, at least longer than LTP. BTW, some weaker
>    components of LTP may last longer than hours, to
>    days (or weeks?) IIRC.

Right.  At 10 nm resolution, you can measure the size of a synapse, 
and with that and the morphology of the postsynaptic process 
(dendritic spine or whatever it may be), you can probably estimate 
the strength.

>3) cell-type information which is the gene activation
>    states as Joe pointed out before. For example the
>    slow-acting neuropeptides that are released by a
>    neuron. This is important because it affects neural
>    dynamics and is stable over a long time (I assume).

Absolutely.  However it appears so far that neuron "types" can mostly 
be distinguished by position and morphology; when we have detailed 
connectivity information, my guess is that that will resolve any 
further difficulties in telling what type of neuron each one is (and 
therefore, what neurotransmitters it produces etc.).  There is so far 
no evidence, as far as I know, that gene activation is actually 
important for memory beyond its obvious effects on cell type and 
morphology.

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