NEURAL SUBSTRATES FOR REPRODUCTIVE BEHAVIOR

性腺类固醇影响成体功能和 行为神经效应器的发展在很大程度上是未知的。我们的目标 是为了确定雄激素是如何引导性分化的 神经系统，从而影响两性性行为。这个 假说是雄激素通过以下方式诱导靶细胞的男性化 获得对某些关键发展过程的控制--扩散， 分化(轴突延伸和突触发生)和细胞死亡。我们 建议研究喉运动发育的性别差异 南非爪蛙非洲爪蛙的神经元。男性展示 在严格的雄激素控制下的性别差异发声行为。这个 影响叫声的肌肉和运动神经元是性二态的， 对荷尔蒙敏感。 该提案旨在研究男女在发声方面的差异。 生理和解剖学技术在成人和成人上的行为 发育中的青蛙。我们将研究不同世代的性别差异 通过刺激喉部运动的传入而发出的叫声模式 记录喉神经上的神经元和活动。喉运动 雄性神经元数量较多，具有广泛的树突； 这些细胞的连接也不同于喉运动神经元 女性。我们将研究喉运动反应的性别差异。 使用细胞内记录的神经元；雄激素对神经元活动的影响 将会被化验。发声运动神经元的性别差异发展 会被解剖检查和男性化的时间点 识别出的事件。我们将尝试将雌性动物的行为斑化 以及通过内分泌操作观察运动神经元的形态。这个 雄激素直接作用与间接作用的相对效应 声带运动神经元的男性化将通过去传入来评估。 以及肌肉靶标的操纵。 这些研究的结果将有助于理解心力衰竭的发病机制。 类固醇在神经功能性分化中的作用。 这些发现将促进我们对生殖功能的了解 性别认同的发展和类固醇药物的作用机制。

The mechanisms whereby gonadal steroids influence the adult function and development of behavioral neuroeffectors are largely unknown. Our goals are to determine how androgenic steroids direct sexual differentiation of the nervous system so as to effect sexually dimorphic behaviors. The hypothesis is that androgen induces the masculinization of targets by gaining control of certain key developmental processes- proliferation, differentiation (neurite extension and synaptogenesis) and cell death. We propose to study the development of sex differences in the laryngeal motor neurons of the South African clawed frog, Xenopus laevis. Males display sexually differentiated vocal behaviors under strict androgen control. The muscles and motor neurons which effect calling are sexually dimorphic and hormone sensitive. The proposal aims to examine male/female differences in generation of vocal behaviors using physiological and anatomical techniques on adult and developing frogs. We will examine sex differences in generation of the vocal pattern, mate calling, by stimulating afferents to laryngeal motor neurons and recording activity on the laryngeal nerve. Laryngeal motor neurons of males are more numerous and have extensive dendritic processes; the connectivity of these cells also differs from larngeal motor neurons of females. We will study sex differences in responses of laryngeal motor neurons using intracellular recording; androgen affects on neuron activity will be assayed. The development of sex differences in vocal motor neurons will be examined anatomically and the time points when masculinization occurs identified. We will attempt to maculinize the behavior of females and the morphology of motor neurons by endocrine manipulation. The relative efficacy of direct versus indirect action by androgens on the masculinization of vocal motor neurons will be assessed by deafferentation and manipulation of muscle targets. Results of these studies will contribute to understanding the mechanism of action of steroids in the sexual differentiation of neuronal function. These findings will advance our knowledge of reproductive function, the development of gender identity and the mechanism of action of steroid drugs.