Ml. Cruz et Bg. Ortegacorona, HYPOTHALAMIC MONOAMINE LEVELS DURING EARLY AND LATE POSTNATAL PERIODSIN MALE AND FEMALE RATS, Medical science research, 25(2), 1997, pp. 75-78
Physiological and biochemical variations in neurotransmitter (NT) syst
ems might be correlated with brain functional and structural sex diffe
rences. To determine the physiological significance of this correlatio
n, we measured the hypothalamic levels of serotonin (5HT) and its meta
bolite 5-hydroxyindolacetic acid (5HIAA), dopamine (DA) and norepineph
rine (NE) by radioenzymatic methods in male and female rats during ear
ly (1-5 days) and late (7-25 days) postnatal periods. Results showed:
(a) Differences in NT levels during both postnatal periods, (b) Change
s in an opposite direction between NE and DA levels and (c) A clear se
x difference in 5HT levels, particularly on day 10. These data suggest
that monoaminergic metabolism may be an important factor contributing
to hormonal and environmental-induced changes (morphological and beha
vioural), that occur during brain sexual differentiation.