Balthazart J, Surlemont C
University of Liège, Laboratory of General and Comparative Biochemistry, Belgium.
Physiol Behav. 1990 Nov;48(5):599-609. doi: 10.1016/0031-9384(90)90198-d.
The sites of androgen and estrogen action on sexual behavior were studied in the preoptic area of castrated male Japanese quail by stereotaxic implantation of hormones, antihormones and metabolism inhibitors. The first experiment demonstrated that bilateral implantation of the aromatase inhibitor, androstatrienedione (ATD), in the sexually dimorphic nucleus (POM) of the preoptic area can completely suppress the behavioral activation produced by a systemic treatment with testosterone. The effects of ATD were only observed if the implants were located in the POM. In the second experiment, implants in the POM of the synthetic estrogen, diethylstilbestrol, restored copulatory behavior in castrated males while implants of the synthetic nonaromatizable androgen, methyltrienolone, were almost ineffective. During the third experiment, the activating effects of a systemic treatment with testosterone were blocked by stereotaxic implants in the POM of the antiestrogen, tamoxifen, or the antiandrogen, flutamide. The effects of tamoxifen were more pronounced than those of flutamide. In addition, tamoxifen was active in all parts of the POM while a behavioral inhibition was observed only for flutamide implants which were located in the caudal part of the nucleus. Taken together, these results demonstrate that the sexually dimorphic POM is the area where the behaviorally active estrogenic metabolites of T have to be produced. The estradiol derived from T aromatization presumably acts within the POM to activate copulation as demonstrated by the effectiveness of DES implanted in this region. Androgens also have a direct action on sexual behavior as suggested by the partial inhibition observed in flutamide-treated birds. It is, however, suggested that androgens and estrogens do not act in the same brain area to activate behavior.
通过激素、抗激素和代谢抑制剂的立体定位植入，研究了雄激素和雌激素对去势雄性日本鹌鹑性行为的作用部位。第一个实验表明，在视前区的性二态核（POM）中双侧植入芳香化酶抑制剂雄甾三烯二酮（ATD），可以完全抑制睾酮全身治疗所产生的行为激活。只有当植入物位于POM时，才能观察到ATD的作用。在第二个实验中，在POM中植入合成雌激素己烯雌酚可恢复去势雄性的交配行为，而植入合成的不可芳香化雄激素甲基三烯olone几乎无效。在第三个实验中，抗雌激素他莫昔芬或抗雄激素氟他胺在POM中的立体定位植入阻断了睾酮全身治疗的激活作用。他莫昔芬的作用比氟他胺更明显。此外，他莫昔芬在POM的所有部位都有活性，而仅在位于核尾侧部分的氟他胺植入物中观察到行为抑制。综上所述，这些结果表明，性二态的POM是必须产生T的具有行为活性的雌激素代谢产物的区域。如在该区域植入己烯雌酚的有效性所示，由T芳香化产生的雌二醇可能在POM内起作用以激活交配。雄激素对性行为也有直接作用，如在氟他胺处理的鸟类中观察到的部分抑制所示。然而，有人认为雄激素和雌激素在激活行为时并非作用于同一脑区。
