Wood R I
Department of Obstetrics & Gynecology, Yale University School of Medicine, New Haven, CT 06520-8063, USA.
Physiol Behav. 1996 Apr-May;59(4-5):833-41. doi: 10.1016/0031-9384(95)02204-x.
In the male Syrian hamster, the medial amygdaloid nucleus (Me) and medial preoptic area (MPOA) are critical for expression of male mating behavior. These regions contain steroid receptor-containing neurons that transduce hormonal signals essential for copulation. In castrated males bearing an intracerebral steroid implant in the MPOA, testosterone or estradiol can facilitate sexual activity. However, DHT is without effect. Testosterone can also stimulate mating when implanted in the Me. The present study determined if estradiol or DHT had behavioral activity in the Me. Twenty adult male hamsters were selected for vigorous sexual behavior. Twelve weeks after castration, sexual behavior was assessed and each male received a single intracranial implant (23-gauge tubing packed with crystalline estradiol or DHT, n = 10 each) placed stereotaxically into posterior Me (MeP). Behavior was examined after surgery to determine if androgens or estrogens in MeP could stimulate sexual behavior above that observed after castration. Mating behavior in DHT-implanted males was not significantly different from castrates. However, males with estradiol implants displayed significantly more copulatory and noncopulatory sexual activity after surgery compared to males with DHT implants. These results suggest that testosterone facilitation of mating behavior in MeP is mediated by aromatization to estradiol, and that DHT is not behaviorally active in this nucleus.
在雄性叙利亚仓鼠中，内侧杏仁核（Me）和内侧视前区（MPOA）对于雄性交配行为的表达至关重要。这些区域含有含类固醇受体的神经元，它们可传导交配所必需的激素信号。在MPOA植入脑内类固醇植入物的去势雄性仓鼠中，睾酮或雌二醇可促进性活动。然而，双氢睾酮（DHT）则无此作用。睾酮植入Me时也可刺激交配行为。本研究确定雌二醇或DHT在Me中是否具有行为活性。选择20只成年雄性仓鼠进行活跃的性行为。去势12周后，评估性行为，每只雄性仓鼠接受一次颅内植入（23号管，填充结晶雌二醇或DHT，每组n = 10），通过立体定位法将其植入Me后部（MeP）。术后检查行为，以确定MeP中的雄激素或雌激素是否能刺激性行为，使其超过去势后观察到的水平。植入DHT的雄性仓鼠的交配行为与去势仓鼠无显著差异。然而，与植入DHT的雄性仓鼠相比，植入雌二醇的雄性仓鼠术后表现出明显更多的交配和非交配性活动。这些结果表明，睾酮对MeP中交配行为的促进作用是通过芳香化转化为雌二醇介导的，并且DHT在该核中没有行为活性。
