ESTROUS-CYCLE IN SEPTAL RAT FEMALES

Bilateral lesions of the dorsal part of the septal area were produced in the brain of female rats of Wistar and Long-Evans stocks. The cytog ram of their vaginal smears was evaluated repeatedly from the 30th day after surgery and permanent impairment of their oestrous cycle was fo und. In comparison with intact control females, oestrous phases were d etected more frequently whereas dioestrous phases were observed less f requently. The proportions between the individual periods of the oestr ous phase (i.e. pro-oestrus, oestrus and metoestrus) were equal in bot h septal and intact animals. No difference was found between the rat s tocks used. Similarly, the previous life history of the rats which had been housed either in a socially impoverished environment (i.e. singl e cages) or in large communities (colonies) exerted no influence upon the postoperative impairment of the oestrous cycle.