New Facts Concerning the Role Played by the Ventromedial Nucleus in the Control of Estrous Cycle Duration and Sexual Receptivity in the Rat

摘要: Bilateral lesions of the ventromedial nucleus(VMN) were performed in 3rd cycle a sequence 4-day cycles Wistar rats by means stereotaxically-oriented platinum unipolar electrodes. Small (SVMN) or large (LVMN) produced passage cathodic current for 7 14 sec, respectively. Groups intact cyclic and 5-day rats, dorsomedial nucleus (DMN) lesioned VMN sham (SH) operated females served as controls. A modification duration one both 2 first post-operative was found 31 out 60 SVMN 11 12 LVMN females. Only 16 DMN none 17 SH exhibited change length. No 4th and/or 5th occurred control non-operated after three cycles. Further study vaginal animals with modified showed that estrous rhythm changed from 4- to alternate following lesions. Ovulation regularly during night proestrus either animals. Neither frequency ovulation nor mean number corpora lutea/rat differed when compared On contrary, significant diminution sexual receptivity resulted comparison (4-day cycles) (5-day cycles). almost completely abolished mating receptivity.