Testosterone metabolism in discrete areas of the hypothalamus and adjacent brain regions of male and female Japanese quail (Coturnix coturnix Japonica).

The metabolism of testosterone in small regions of the hypothalamus was studied by an in vitro radioenzymatic assay in male and female Japanese quail. 5 beta-reduction was the most important metabolic pathway. This enzymatic activity is not evenly distributed in the brain: it shows a rostral to caudal decrease. There is some suggestion that 5 beta-reduction could be more active in females than in males which could contribute to the behavioral dimorphism in this species.