[Neuroscience] Re: Electrical Synapses..

r norman NotMyRealEmail at _comcast.net
Tue Feb 28 09:31:40 EST 2006


On Mon, 27 Feb 2006 22:27:31 +1100, Matthew Kirkcaldie
<m.kirkcaldie at removethis.unsw.edu.au> wrote:

>In article <8cpnv11877uv17u7bj2118799sudpenhs4 at 4ax.com>,
> r norman <NotMyRealEmail at _comcast.net> wrote:
>
>> However the neglect is probably well deserved.  They do exist in both
>> vertebrates (including humans) and invertebrates and some very special
>> connections do use electrical synapses, but they are basically very
>> boring.  The chemical synapses do all the "heavy lifting" in nervous
>> calculations, because they have the ability to be much more easily
>> modulated by a variety of causes including prior activity.  So
>> interesting things like learning and memory must really be due to
>> chemical synapses, not electrical ones.
>
>Not sure I'd concur on that front - there is an increasing body of 
>evidence that suggests (a) inhibitory neurons in cortex are massively 
>interconnected by electrical as well as chemical synapses, and (b) that 
>this combination of electrical excitation and lagging chemical 
>inhibition produces non-linear coupling, so that some types of activity 
>and excitation get propagated through the network. It creates an 
>environment in which particular frequencies of activity spread more 
>easily than others, and I'm sure you would agree that has great 
>possibilities for influencing the "interesting things"!  Especially when 
>you consider that it seems that the favoured frequencies are in the 
>magical "gamma band", much beloved of consciousness speculators.
>
>There are some good reviews by Hestrin and Galaretta I think - also some 
>of the work has come from Peter Somogyi's lab I think.
>
>      Cheers, MK.

Many thanks for this information.   The changes that occur during
learning and memory may be primarily due to metabotropic chemical
synapses but, as you say, the interaction between electrical and
chemical might well produce extremely interesting events that might
well be an important part of the story we do not yet fully understand.






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