The role of sexually dimorphic medical preoptic area of the hypothalamus in the sexual behaviour of male and female rats.
The neonatally gonadectomized male rats failed to show typical male clasping of the flanks of the female rat in oestrous stage and also could not achieve intromission and ejaculation when studied at 90 days of age. The replacement of testosterone propionate did not abolish the deficit in sexual behaviour observed. The multiunit electrical activity (MUA) in the medial preoptic area (MPOA) of intact males as well as of oestrous females increased significantly in amplitude and frequency from the low basal levels during mounting, but reverted almost to the basal levels after mounting. The basal MUA in the gonadectomized male rats was of relatively high frequency and amplitude when compared to the intact males and oestrous females, and did not show significant changes during and after mounting. It is suggested that the dimorphic organization of MPOA, developing under the influence of neonatal testosterone, plays a significant role in the male sexual behaviour in adulthood.
Kartha
K N
KN
Department of Life Sciences, University of Calicut, Kerala, India.
Ramakrishna
T
T
D000818:Animals; D000831:Animals, Newborn / Q000502:physiology; D004567:Electrodes, Implanted; D004569:Electroencephalography; D004594:Electrophysiology; D005260:Female; D006128:Growth / Q000502:physiology; D008297:Male; D009919:Orchiectomy; D010052:Ovariectomy; D011301:Preoptic Area / Q000033:anatomy & histology / Q000254:growth & development / Q000502:physiology*; D051381:Rats; D017208:Rats, Wistar; D012727:Sex Characteristics; D012726:Sexual Behavior, Animal / Q000502:physiology*; D013739:Testosterone / Q000494:pharmacology
D013739:Testosterone