[Neuroscience] Re: Electrical Synapses..
jkrah_dot_geo_ at yahoo_dot.com
Thu Mar 2 19:03:13 EST 2006
Thanks Matthew for your response also.. Im starting to think this may be
an area (importance of elec synapse) of debate in coming years..
The other day I read (and please remember I am really a beginner) that
GapJuncions (ie elect synapse) can potentially also allow the transfer
of larger molecules ie transmitters / 2nd Messenger molecules etc..
Surely this also had some huge potential for the (long term) modulation
The thing I find really interesting (and complex) is the Integrative
functions of these gap junctions.. reading about the Leech S-Cell
network (& effects of 5ht in learning) - it seems that when a group of
cells is tightly coupled by gap-junctions - they can be thought of
effectively one-big-cell.. now if massive connected area of cells exist
(eg cortex) - can these also be considered to be acting like single
neural entities ???
on a side note - I read about the ability of a axonal branch to delay
and then reflect a AP back up the main axon the other day.. Im starting
to think that in Neurobio - if soemthing is remotely physically possible
.. then its probably happening somewhere.. I love this stuff..
Thanks again for you feedback guys!!! .. I feel priveiged to be able to
ask these things to poeple 'in the know'..
r norman wrote:
> 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 inMK teraction 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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