Androgens reduce cell death in the developing rat visual cortex

We have previously shown that males have more neurons than females in the p rimary visual cortex, and neonatal androgens play an important role in this difference. Also, we have found that females experience more cell death du ring development in this region than in males. Therefore, we hypothesized t hat the neonatal hormone environment directly influences the amount of cell death. In the present experiment, female rats were implanted with dihydrot estosterone (DHT) or estradiol at postnatal day 1. These animals, along wit h control males and females, were sacrificed on postnatal days 6, 11 and 25 . Using unbiased stereology to quantify neuronal and pyknotic cell density, we observed that females implanted with DHT had a similar pattern and prop ortion of cells dying as control males. Additionally, developmental cell de ath in females implanted with estradiol was not significantly different tha n control females. Thus, neonatal androgens have an inhibitory effect on de velopmental cell death in the rat primary visual cortex. (C) 2000 Elsevier Science B.V. All rights reserved.