Different neuronal and glial cell groups in corticomedial amygdala react differently to neonatally administered...

The percentage of labeled neurons and glial cells in the phylogenetically older corticomedial part of the amygdala was investigated in control and estrogen-treated rats using [3H]thymidine autoradiography. Newborn, three-day-old female and male Wistar rats were treated with a single dose of 1 mg of estrogen and killed at the age of 10 days. The percentage of labeled neuronal and glial cells was determined by stereological methods in the medial, cortical and central nuclei, respectively. In treated male rats, the percentage of labeled neurons and glial cells in these nuclei was significantly greater on the 10th day of life as compared to controls, except for glial cells in the nucleus centralis. In treated female rats, the percentage of labeled neurons in all three nuclei was comparable to controls, while the percentage of labeled glial cells was increased in the nucleus medialis, decreased in the nucleus centralis and unchanged in the nucleus corticalis. Our results indicate clear sex- and region-specific differences in the reactivity of both neurons and glia to neonatally administered estrogen.