Bodo Cristian, Rissman Emilie F
Department of Biochemistry & Molecular Genetics and Graduate Program in Neuroscience, University of Virginia, Charlottesville, VA 22908, USA.
Eur J Neurosci. 2007 Apr;25(7):2182-90. doi: 10.1111/j.1460-9568.2007.05484.x.
During sexual differentiation males and females are exposed to different levels of testosterone, which promotes sex differences in the adult brain and in behavior. Testosterone can act after aromatization or reduction via a number of steroid hormone receptors. Here we provide new evidence that the androgen receptor (AR) is essential for sexual differentiation in mice. We used mice carrying the testicular feminization (Tfm) mutation of the AR. Adult Tfm males, wild-type male and female littermates were gonadectomized and given subcutaneous estradiol implants. In all sexually dimorphic traits, Tfm males had responses equivalent to females and different from males. In simultaneous choice tests, males spent significantly more time investigating female-soiled bedding, whereas females and Tfm males preferred to investigate male-soiled bedding. Tfm males and females did not have a partner preference in tests with awake stimulus animals, whereas males showed a preference for females over males. Exposure to male-soiled, but not clean, bedding produced a significant increase in c-Fos-immunoreactive cells in the medial preoptic area and bed nucleus of the stria terminalis in Tfm males and females, no increase was noted in males. Masculine sexual behavior (mounting and thrusting) was not sexually dimorphic, and all groups displayed these behaviors. Our results support data collected in humans suggesting a role for the androgen receptor in sexual differentiation of social preferences and neural responses to pheromones.
在性别分化过程中，雄性和雌性接触到不同水平的睾酮，这会促进成年大脑和行为中的性别差异。睾酮可通过多种类固醇激素受体在芳香化或还原后发挥作用。在这里，我们提供了新的证据，表明雄激素受体（AR）对小鼠的性别分化至关重要。我们使用了携带AR睾丸雌性化（Tfm）突变的小鼠。对成年Tfm雄性小鼠、野生型雄性和雌性同窝小鼠进行性腺切除，并给予皮下植入雌二醇。在所有性二态性特征方面，Tfm雄性小鼠的反应与雌性小鼠相当，与雄性小鼠不同。在同时选择测试中，雄性小鼠花费显著更多时间探究雌性弄脏的垫料，而雌性小鼠和Tfm雄性小鼠则更喜欢探究雄性弄脏的垫料。在与清醒刺激动物的测试中，Tfm雄性小鼠和雌性小鼠没有伴侣偏好，而雄性小鼠表现出对雌性的偏好超过对雄性的偏好。暴露于雄性弄脏而非干净的垫料中，会使Tfm雄性小鼠和雌性小鼠视前内侧区和终纹床核中c-Fos免疫反应性细胞显著增加，而雄性小鼠中未观察到增加。雄性性行为（骑跨和 thrusting）不存在性二态性，所有组都表现出这些行为。我们的结果支持在人类中收集的数据，表明雄激素受体在社会偏好的性别分化和对信息素的神经反应中发挥作用。 （注：“thrusting”在文中结合语境推测为性行为中的一个动作，但在医学文献里可能有更专业准确的术语，此处保留英文以确保准确性）
