Panzica G C, Viglietti-Panzica C, Calacagni M, Anselmetti G C, Schumacher M, Balthazart J
Brain Res. 1987 Jul 21;416(1):59-68. doi: 10.1016/0006-8993(87)91496-x.
We recently identified a sexually dimorphic nucleus in the preoptic region of the Japanese quail, the medial preoptic nucleus (POM), which is significantly larger in males than in females. In the present study, we investigated the hormonal control of this morphological neuroanatomical difference and the possible relationships between the sexual dimorphism in POM volume and in copulatory behavior. Treatments which are known to affect sexual behavior were thus applied to different groups of birds and the POM volume was then measured. In one experiment, male and female quails were either gonadectomized, gonadectomized and treated with testosterone or left intact. The larger size of the POM in males was confirmed and treatments significantly affected the nucleus size which was decreased by gonadectomy and restored by testosterone treatment in both sexes to a level similar to that seen in intact males. In two other experiments, eggs were injected with estradiol benzoate on day 9 of incubation and the POM volume was measured in adulthood either in intact birds or in gonadectomized birds receiving a replacement therapy with testosterone. Despite the fact that estradiol benzoate treatment completely suppressed copulatory behavior, it did not affect the volume of the POM or slightly increased it. These data thus show that the POM volume is controlled by testosterone levels in adulthood and could thus be an interesting model for the study of the effects of steroids on the brain.
我们最近在日本鹌鹑的视前区发现了一个性别二态核团，即内侧视前核（POM），雄性的该核团明显大于雌性。在本研究中，我们调查了这种形态学神经解剖学差异的激素控制，以及POM体积的性别二态性与交配行为之间的可能关系。因此，将已知会影响性行为的处理应用于不同组的鸟类，然后测量POM的体积。在一项实验中，对雄性和雌性鹌鹑进行性腺切除、性腺切除并用睾酮处理或保持完整。证实了雄性POM的较大尺寸，并且处理显著影响了核团大小，性腺切除使核团大小减小，睾酮处理使两性的核团大小恢复到与完整雄性相似的水平。在另外两项实验中，在孵化第9天给蛋注射苯甲酸雌二醇，在成年期测量完整鸟类或接受睾酮替代疗法的性腺切除鸟类的POM体积。尽管苯甲酸雌二醇处理完全抑制了交配行为，但它并未影响POM的体积，或使其略有增加。因此，这些数据表明成年期POM体积受睾酮水平控制，因此可能是研究类固醇对大脑影响的一个有趣模型。
