ENVIRONMENTAL INFLUENCES ON BRAIN PLASTICITY

描述（改编自申请人摘要）：本研究涉及 是什么决定了行为的变化 许多 环境变量可以对表型产生可预测的影响。 一 许多爬行动物卵的孵化温度就是这样的变量。 在 在豹纹壁虎中，胚胎变成雄性或雌性取决于它们的 发展过程中的温度。 此外，两性之间以及 性别内的差异归因于孵化温度已经 在形态学、类固醇激素的分泌和敏感性中发现， 社会性行为，生殖成功，以及神经解剖学和 调节社会性行为的大脑区域的代谢活动。 这些 环境效应类似于子宫内 哺乳动物，包括人类。 假设 内分泌系统和神经系统，重要的是， 确定是否同源机制是这些类似作用的基础， 行为 如果环境影响行为的机制 豹壁虎是保守的（即，通过性类固醇），这项研究将 为性别分化的进化提供了新的见解， 温度依赖的性别决定被认为是进化的 基因型性别决定的前体（存在于鸟类和哺乳动物中）， 因为爬行动物是鸟类和哺乳动物的祖先。 如果 机制不同（即，直接温度效应），这项研究 将阐明一种新的性别分化过程， 存在于鸟类和哺乳动物中，但由于恒温，被掩盖了。 这 后一种可能性尤其重要，因为幼鸟和哺乳动物 不能像成年人那样调节体温。 拟议研究 大致可分为三类：体温调节及其关系 社会性行为（即，神经基质 介导体温调节和社会性行为重叠）， 这些大脑区域和激素的神经表型的发展 环境，以及发育过程中激素调节的影响， 成年期对体温调节和社会性行为的神经操纵 行为。 最后一类实验特别重要， 它将辨别孵化温度的影响是直接的还是 间接的

DESCRIPTION (Adapted from applicant's abstract): This research addresses the fundamental question of what determines behavioral variation. Many environmental variables can produce predictable effects on phenotype. One such variable is the incubation temperature of eggs in many reptiles. In the leopard gecko, embryos become male or female depending upon their temperature during development. In addition, between-sex as well as within-sex differences attributable to incubation temperature have been found in morphology, secretion of and sensitivity to steroid hormones, sociosexual behavior, reproductive success, and in the neuroanatomy and metabolic activity of brain areas that mediate sociosexual behaviors. These environmental effects are analogous to the effect of intrauterine environment in mammals, including humans. Given the homology of the endocrine and nervous systems across vertebrates, it is important to determine if homologous mechanisms underlie these analogous effects on behavior. If the mechanism underlying environmental effects on behavior in the leopard gecko is conserved (i.e., via sex steroids), this research will lend new insight into the evolution of sexual differentiation because temperature-dependent sex determination is thought to be the evolutionary precursor to genotypic sex determination (present in birds and mammals) and because reptiles are the ancestors of both birds and mammals. If the mechanism is different (i.e., direct temperature effects), this research would elucidate a novel process of sexual differentiation that may also be present in birds and mammals but, because of homeothermy, is masked. This latter possibility is especially important because young birds and mammals cannot regulate their body temperature as do adults. The proposed research is broadly categorized into three groups: thermoregulation and its relation to sociosexual behaviors (i.e., the degree to which the neural substrates mediating thermoregulatory and sociosexual behavior overlap), the development of the neural phenotypes of these brain regions and hormone milieus, and the effects of hormonal manipulations during development and neural manipulations in adulthood on thermoregulatory and sociosexual behaviors. The final category of experiments is particularly important as it will discern whether the incubation temperature effects are direct or indirect.