Regional specificity in estradiol effects on [3H]uridine incorporation in rat brain

In this study, the effects of 15 days of estradiol (E2) on tritiated-uridine incorporation were autoradiographically examined, on a cell-by-cell basis, in 4 E2-concentrating regions of the female rat brain. These areas included the ventromedial hypothalamus and medial amygdala nucleus, 2 regions involved in the behavioral components of reproduction, and the medial preoptic area and arcuate nucleus of the hypothalamus, 2 regions involved in the endocrine components of reproduction. Chronic E2 caused a 50% and 52% increase in tritiated-uridine incorporation in the arcuate nucleus and medial preoptic area, but was without effect in the ventromedial hypothalamus and medial amygdala nucleus. Somal area was also increased with E2 in the arcuate nucleus and medial preoptic area (16% and 43%, respectively) but not in the ventromedial hypothalamus and medial amygdala nucleus. The results indicate that the effects of estradiol on levels of newly synthesized RNA vary in a functionally and regionally specific manner within the brain.