Perinatal administration of testosterone induces hypertrophy of the anterior commissure in adult male and female rats.

A possible sex difference in the mean sagittal area of the anterior commissure (AC) was investigated in normal, newborn-castrated, and perinatally-androgenized rats. A second experiment included castrated adult rats from each sex exposed to testosterone twelve days before sacrifice. In normal rats, as well as in those exposed to testosterone as adults, no quantitative difference was found in the AC. However, perinatal exposure to testosterone induced a 20-25% increase in the mean area of the AC of rats from each sex. It is proposed that gonadal sex steroids may have a reciprocal influence upon the structure of central olfactory pathways, due to the influences of the main olfactory system upon gonadotropin secretion.