Thanks a lot.
Anyway, I may have not explain correctly what I wanted, or I don't
understand well enough what you say.
I have some basic notions about neurons and chemistry, but I haven't tried
to know the whole phenomena of the synapse.
Here is what I wanted know if it was possible :
Neuron A is activated since a few msec (or less or even more).
Neuron A suddenly desactivates.
Wait some msec.... (delay, no signal in A's axon, nor through Synapse S)
Synapse S from neuron A (still desactivated) to neuron B then transmits a
signal.
Is that the same delay you were talking about ?
If this is possible, can the delay be very long ?
Laurent
"Richard S. Norman" wrote:
> On Tue, 16 Jul 2002 15:24:03 +0200, Laurent
> <lorseau at ens.insa-rennes.fr> wrote:
>> >Hi !
> >
> >I was wondering if a natural synapse could transmit a signal after and
> >only after (and not instantly after) the source neuron has stopped being
> >activated. Is this possible ?
> >
> >Laurent.
>> Your question can be answered on many different levels of detail. How
> much neurophysiology background do you have and how much detail do you
> want? Are you really asking about synaptic delay?
>> Generally, the synapse releases transmitter as a result of being
> depolarized. In many cases, that means that the axon has just fired
> an action potential. The nerve activity causes the transmitter
> release by starting a complex process involving calcium and vesicle
> changes (here is where all the details occur).
>> It does take a brief time to crank up the machinery and here is where
> most of the synaptic delay occurs. But if the action potential is
> prolonged a bit, it is certainly possible for the transmitter to be
> released before the action potential is finished, if that is what you
> are asking. The delay can vary from a few hundred microseconds to a
> msec or more depending on the cell and the synapse and the action
> potential can have a similar variation in duration.
>> The most important thing is the the release machinery does not require
> that the depolarization be removed before release can occur. So, yes,
> it is possible.
