抄録
The neural mechanism of the hypothalamus in the regulation of the reproductive function in rats was studied from the view point of the choline acetylase activity in the brain. The cyclic fluctuation in the enzyme activity during the estrous cycle and the marked increase in the activity following castration in the hypothalamus were found. The fluctuation of the enzyme activity was somewhat different between the anterior-and the posterior hypothalamus; the former mainly consisted the cyclic fluctuation of the enzyme activity in the whole hypothalamus during the estrous cycle, and the latter caused the elevation following castration. Sex difference in the pattern of the change of the choline acetylase activity in castrated animals was also observed. The fluctuations in the hypothalamic choline acetylase activity observed in this study would suggest an importance of the role of the cholinergic enzyme system in the by pothalamus in the reproductive function.
