More and more reports in recent years have shown that the intake of
polyunsaturated fatty acids (PUFA) constitutes an environmental factor
able to act on the central nervous system (CNS) function. We recently
demonstrated that the effects of PUFA on behavior can be mediated
through effects on the monoaminergic neurotransmission processes.
Supporting this proposal, we showed that chronic dietary deficiency in
alpha-linolenic acid in rats induces abnormalities in several parameters
of the mesocortical and mesolimbic dopaminergic systems. In both
systems, the pool of dopamine stored in presynaptic vesicles is strongly
decreased. This may be due to a decrease in the number of vesicles. In
addition, several other factors of dopaminergic neurotransmission are
modified according to the system affected. The mesocortical system seems
to be hypofunctional overall [e.g., decreased basal release of dopamine
(DA) and reduced levels of dopamine D2 (DAD2) receptors]. In contrast,
the mesolimbic system seems to be hyperfunctional overall (e.g.,
increased basal release of DA and increased levels of DAD2 receptors).
These neurochemical changes are in agreement with modifications of
behavior already described with this deficiency. The precise mechanisms
explaining the effects of PUFA on neurotransmission remain to be
clarified. For example, modifications of physical properties of the
neuronal membrane, effects on proteins (receptors, transporters)
enclosed in the membrane, and effects on gene expression and/or
transcription might occur. Whatever the mechanism, it is therefore
assumed that interactions exist among PUFA, neurotransmission, and
behavior. This might be related to clinical findings. Indeed, deficits
in the peripheral amounts of PUFA have been described in subjects
suffering from neurological and psychiatric disorders. Involvement of
the monoaminergic neurotransmission function has been demonstrated or
hypothesized in several of these diseases. It can therefore be proposed
that functional links exist among PUFA status, neurotransmission
processes, and behavioral disorders in humans. Animal models are tools
of choice for the understanding of such links. Improved prevention and
complementary treatment of neurological and psychiatric diseases can be
expected from these studies.
Reference:
Polyunsaturated fatty acids and cerebral function: focus on monoaminergic neurotransmission.
Omega-3 fatty acids and monoamine neurotransmission.
Dietary fish oil affects monoaminergic neurotransmission and behavior in rats.
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