basic question

Kevin Spencer kspencer at
Mon Sep 30 17:07:39 EST 1996

pfliegej at ERE.UMontreal.CA (Pflieger Jean-Francois) writes:

>First, synapses are not always unidirectional: a) Gap-junction are 
>bidirectional (even if not equally in the two direction, and b) a large 
>number of molecules which could act as retrograde messengers are now known 
>(arachidonic acid, NO...), and evidence accumulates for their role as 
>retrograde messengers. Second a antidromic action potential is 
>(generally?) stoped by the absence of Na-voltage dependent channels in the 
>body and dendrites of neurons. Third, an antidromic impulse could, 
>theorically, inhibit a receptor or synaptic potential; but I don't know 
>if there is proof or example for that. 

There have been studies in recent years demonstrating evidence that
action potentials can indeed propagate back up the dendritic tree.  I
don't have any references nearby, but the papers I've seen were published
in Science a/o Nature.  This could indeed be a mechanism by which the
firing of a neuron modulates the inputs it receives.

Kevin Spencer
Cognitive Psychophysiology Laboratory and Beckman Institute
University of Illinois at Urbana-Champaign
kspencer at

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