Neuroendocrine Regulation of Behavioral Differences

生殖行为的性别和季节差异往往被控制它们的结构形态的差异所掩盖。 虽然这种二态性是许多脊椎动物的基本特征，但所涉及的机制似乎各不相同。 类固醇激素通常介导解剖学和功能，但生物体在哪种激素是重要和关键的年龄和性别方面存在差异。 这些差异中的一些可能反映了动物或其环境所施加的约束，但其他差异可能反映了系统的类型（例如，求爱或交配）。 本实验旨在研究绿色变色蜥蜴雄性生殖行为的两个神经肌肉系统。 雄性会伸出一个喉扇（垂肉）向雌性求爱，控制这种展示的运动神经元和肌肉有几个雄性偏向的特征。 类固醇激素调节这些结构的分化的假设将被测试，并且将确定具体涉及的激素，从而确定它们何时何地起作用。 雄性在交配过程中也会使用两种半烯中的一种，这两种半烯由两对肌肉控制。 成年女性没有这些结构。 相关的脊髓运动神经元更大，数量更多的男性。 与成年期稳定的赘肉系统不同，初步结果表明，至少成年雄性的交配肌肉是可塑的。 实验将研究交配肌和运动神经元是否在繁殖季节和非繁殖季节之间发生形态学变化，以及这些变化是否可以由睾酮诱导。 然后，对于垂肉系统，性激素在交配神经肌肉结构的性分化中的作用将被评估。 求偶系统在幼鱼中存在差异，而交配系统在孵化时具有性二态性。这项提案将解决一个重要的问题，“为什么有些系统对性腺激素的反应性减弱，而另一些系统在发育过程中和成年后仍保持可塑性？“.拟议工作的更广泛影响包括通过增进对神经系统和肌肉结构塑造所涉机制的了解，在发育组织和成人可塑性方面推进科学发现。与此同时，将促进教学、培训和学习，鼓励代表性不足的群体参与实验室工作，及时传播科学成果，并加强这所大学神经内分泌研究的基础设施。

Gender and seasonal differences in reproductive behaviors are often paralleled by differences in the morphology of structures controlling them. Although such dimorphisms are fundamental characteristics of numerous vertebrates, the mechanisms involved appear to vary. Steroid hormones often mediate both anatomy and function, but organisms differ in which hormone is important and critical age and in which sex it acts. Some of these differences may reflect constraints imposed by the animals or their environments, but others may reflect the type of system (e.g., courtship or copulatory). The proposed experiments investigate two neuromuscular systems required to coordinate a suite of masculine reproductive behaviors in green anole lizards. Males extend a throat fan (dewlap) to court females, and the motoneurons and muscles controlling this display have several male-biased characteristics. The hypothesis that steroid hormones regulate differentiation of these structures will be tested, and hormones specifically involved will be identified, thus determining when and where they act. Males also use one of two hemipenes during copulation, which are controlled by two pairs of muscles. Adult females do not have these structures. Relevant spinal motoneurons are larger and more numerous in males. Unlike the dewlap system, which appears stable in adulthood, preliminary results suggest that at least the copulatory muscles are plastic in adult males. Experiments will investigate whether the copulatory muscles and motoneurons change morphologically between the breeding and non-breeding seasons, and whether these changes can be induced by testosterone. Then, as for the dewlap system, the role of gonadal hormones in sexual differentiation of the copulatory neuromuscular structures will be assessed. The courtship system differentiates in juveniles, whereas the copulatory system is sexually dimorphic at hatching. This proposal will address the important question, "Why do some systems loose their responsiveness to gonadal hormones while others remain plastic during development and into adulthood ?".The broader impacts of the proposed work involve advancing scientific discovery by increasing the understanding of mechanisms involved in sculpting the structure of the nervous system and muscles, both in developmental organization and adult plasticity. At the same time teaching, training, and learning will be promoted, the participation of underrepresented groups in lab work will be encouraged, scientific result will be disseminated in a timely fashion, and the infrastructure for neuroendocrine research at this university will be enhanced