It is found in enterochromaffin cells, platelets
and in the brain. In the brain it is found mainly in the hypothalamus but
there are special serotoninergic neurons which are neurotransmitter agents
which extend from the raphe nuclei of the brain stem to the hypothalamus,
limbic system, the neocrotex and the cerebellum. Disruption, of the
synthesis, storage and release of serotonin causes some behavioral problems
as the following will prove:
Lysergic acid diethylamide (LSD) which is a
serotonin antagonist causes psycheielic phenomena.
Other tryptamine derived substances have
psychotomimetic actions e.g. psilocybin.
Reserpine causes depletion of serotonin in the
brain. It acts as a tranquillizer and also causes depression.
Monoamien oxidase inhibitors which are
naturally supposed to break down excess monoamine cause accumulation of
serotonin when used in treatment of depressive psychoses and therefore
Serotonin plays important role in regulation
of some APUD hormone secretion e.g. adreno-hypophyssseal hormones.
Serotonin inhbits autonomic impulses in the
intermedio-lateral column of the spinal cord.
Considerable amount of serotonin in the
hypothalamus (which may be considered the leader of the diffuse
neuroendocrine system) suggests a possible modulation of activity of the
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Creator: Oluwole Ogunranti