Neuron / neurotransmitter selection question

John H. johnh at faraway.xxx
Thu Feb 27 03:22:05 EST 2003


Last year I did read some research to the effect that administration of BDNF
switched a cardiac neuron from excitatory to inhibitory function in under 15
minutes. Sounds weird I know and have no idea about how it could work. If
you like will try to find the reference in my archives. No, here it is

04/07/02 6:50
Nature Neuroscience
Published online: 6 May 2002, doi:10.1038/nn853
June 2002 Volume 5 Number 6 pp 539 - 545

A rapid switch in sympathetic neurotransmitter release properties mediated
by the p75 receptor

Bo Yang1, 2, John D. Slonimsky1, 2 & Susan J. Birren1

1. Department of Biology, Volen Center for Complex Systems, 415 South St.,
M/S 008, Brandeis University, Waltham, Massachusetts 02454, USA
2. The first two authors contributed equally to this work.
Correspondence should be addressed to S J Birren. (e-mail:
(/neuro/email_response/email.taf?address=birren%40brandeis.edu))
Cardiac function is modulated by norepinephrine release from innervating
sympathetic neurons. These neurons also form excitatory connections onto
cardiac myocytes in culture. Here we report that brain-derived neurotrophic
factor (BDNF) altered the neurotransmitter release properties of these
sympathetic neuron-myocyte connections in rodent cell culture, leading to a
rapid shift from excitatory to inhibitory cholinergic transmission in
response to neuronal stimulation. Fifteen minutes of BDNF perfusion was
sufficient to cause this shift to inhibitory transmission, indicating that
BDNF promotes preferential release of acetylcholine in response to neuronal
stimulation. We found that p75-/- neurons did not release acetylcholine in
response to BDNF and that neurons overexpressing p75 showed increased
cholinergic transmission, indicating that the actions of BDNF are mediated
through the p75 neurotrophin receptor. Our findings indicate that p75 is
involved in modulating the release of distinct neurotransmitter pools,
resulting in a functional switch between excitatory and inhibitory
neurotransmission in individual neurons
--

This is a good example, however, of the variability of neural transmission.
MANY factors can affect neurotransmitter release, some people in computers
tend to assume that a neuron's function is 'fixed'. I wish, that would make
so much that much easier. To my knowledge the above is the only reference I
have seen to this change in function. Your question may be somewhat
academic, many neurons receive multiple inputs from a variety of other
neurons, altering action potentials this way and that. For excellent egs of
this have a look at Goldman-Rakic's work on prefrontal circuitry. If you
wish can forward references for free downloads of the relevant articles but
warned you'll be quickly confused. I'm happy to leave such problems to minds
bigger than mine.


John H.

"Neo" <neo55592 at hotmail.com> wrote in message
news:4b45d3ad.0302242023.28eb8978 at posting.google.com...
> My background is in computers and not in biology so my question may
> seem off. I would like to know if a neuron can select which
> neurotramitter to release in synapses. Can a neuron select different
> neurotranmitter for each action potential? How/why does a neuron
> select different neurontransmitters?





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