Sensory perception (neurobiology query)
kr4 at is2.nyu.edu
Thu Aug 20 10:39:34 EST 1998
Ted (edh at no.spam.thanks.oitunix.oit.umass.edu) wrote:
> I think you're confusing action potentials with postsynaptic
> potentials. Very briefly, action potentials are conducted along axons
> after neural integration, which occurs at the base of the axon. Action
> potentials are "all-or-nothing" events; either they occur, or they
> don't. When they occur, they travel down the axon and induce the
> release of neurotransmitters (or neuromodulators) at the axon's terminal
> button, where the neuron synapses with another neuron.
> Postsynaptic potentials (PSPs) occur in dendrites or the membrane of the
> cell body as the result of receiving a chemical message from another
> neuron. They may be of varying strength, and are "summed up" in the
> neural integration that occurs at the axon's base. PSPs may either
> excite or inhibit the generation of an action potential.
OTOH, while not exactly action potentials, there are dendritic spikes which are generated
by patches of voltage-gated channels found in some neurons if the voltage of the summed
PSPs is sufficient.
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