| dc.description.abstract | Present data indicates that hormones especially
corticosteroids, apart from being responsible for
functional changes in the CNS, also bring about changes
which alter the general metabolism of the brain, thus
affecting different aspecLs of the neurotransmitter,
plastic and energetic functions of the neurone. It
is generally accepted that one of the most plastic
morphofunctional structures of the CNS is the synapse,
and most neurotropic compounds including steroid hormones
affect neuronal activity and other associated
structures by affecting synaptic transmission. Hormones
can alter the levels of neurotransmitters in
certain regions of the central and peripheral nervous
system by either altering their data of synthesis or
degradation, i.e. by affecting the activities of the
enzymes responsible for their metabolism.
The study has examined the metabolism of several
biogenic amines GABA, Nlrepinephrine (NE) Dopamine
(OA) and Serotonin (S-Hl) and how their metabolism is
affected by different corticosteroid leve~. In an
attempt to elucidate the biochemical basis of behavioural
effects of corticosteroids, we have studied
t he influence of two of these hc r-mo ne s . hy dr-o co rt isone
and dexamethasone on the relative concentrations of
NE, OA, 5-HT and GABA and their metabolic enzymes in
discrete regions of the brain with special emphasis
being paid to the limbic structures especially the
hypothalamus and hippocampus. We used a model of
single and mUltiple administration of high doses of
the hormones which causes hyper and hypocortisolism
in blood plasma respectively. We have also studied
how the metabolic enzymes vary under these hormonal
conditions.
The results of our study show that alteration
of corticosteroid status of rats, does cause changes
in the concentrations of the putative neurotransmitters
sufficient to cause gross behavioral changes. The
data also indicates that changes seen in brain NE, OA,
5-HT and GABA are modulated through adrenocortical
steroids and that these hormones playa role in the
regulation of biogenic amine metabolism. It is suggested
that corticosteroids could be used in therapy
of affective disorders.
The work is original and helps to expand and
shed more light on available data on the control of
neurolransmitter metabolism by steroid hormones and
possible control mechanisms. | en |
