P. Szot et Dm. Dorsa, DIFFERENTIAL TIMING AND SEXUAL DIMORPHISM IN THE EXPRESSION OF THE VASOPRESSIN GENE IN THE DEVELOPING RAT-BRAIN, Developmental brain research, 73(2), 1993, pp. 177-183
The ontogeny of vasopressin (VP) gene expression in extrahypothalamic
neurons of the bed nucleus of the stria terminalis (BNST) and medial a
mygdala (MA) was investigated using in situ hybridization. In both the
BNST and MA, VP mRNA-positive cell profiles were only detected a few
days after birth. In males, VP mRNA-expressing cell profiles appear in
the BNST on day 3 and in the MA on day 5. In contrast, hybridization
signals could not be detected in the female brain until day 14 in the
BNST and day 35 in the MA. Adult VP mRNA levels are attained by day 35
in the BNST and day 60 in the MA for both sexes. From this data, it i
s apparent that development of the VP system is delayed in females com
pared to the males. Therefore, these data suggest that the sexual dimo
rphic pattern in the expression of VP mRNA in these nuclei of the adul
t brain is evident early in the developmental process.