COMPARATIVE STUDIES OF VOCAL CONTROL

描述（改编自申请人的摘要）： 神经系统的一个基本特征是它们提供了神经系统的可塑性。 结构和功能，使动物能够适应他们的变化， 环境我们才刚刚开始了解潜在的机制， 限制，以及行为后果，如学习，自然的 大脑的可塑性鸟类大脑中的鸣唱控制系统 为解决这些基本的行为问题提供了极好的机会， 神经科学环境因子的季节变化，如光周期， 对鸟类和大多数其他动物都有深远的影响。在鸣禽季节性 光周期的变化引起性腺激素循环浓度的变化， 类固醇激素，这反过来又会导致歌曲行为的变化， 神经内分泌系统的形态和生理属性， 控制歌曲。个体之间的社会线索交换增强了 在繁殖季节的歌曲系统的增长。这项提案的目的是 是用比较的方法来探讨近似的机制， 鸟类鸣唱控制系统的季节可塑性行为功能。 我们将确定是否社会增强的季节性增长的 鸣唱神经核是由听觉刺激介导的。我们将研究社会是否 来自其他鸟类的刺激增强了鸣唱核的生长， 增加脑内新产生的神经元的募集和/或存活， 成鸟的鸣唱系统为了检验季节性维持的假设， 鸣唱核团的发育依赖于传入核团的神经支配， 处于繁殖光周期的金丝雀单侧HVc核 并比较RA和X区传入核团的形态 病变的同侧和对侧。假设季节性的 鸣唱核的生长受雌激素代谢物的调节， 睾酮将通过测量鸣唱核的形态学来测试， 行为和血浆激素水平的影响 服用不同的类固醇。我们将使用操作性条件反射技术， 测试这一假设，季节性变化的歌曲感知功能 与歌曲系统的季节性可塑性有关。建议的结果 研究将增加我们对类固醇激素和社会的理解 对神经系统的影响，以及可塑性之间的关系， 成人的大脑和学习

DESCRIPTION (Adapted From The Applicant's Abstract): A fundamental feature of nervous systems is that they provide plasticity of structure and function which allows animals to adapt to changes in their environment. We are only beginning to understand the underlying mechanisms, the limitations, and the behavioral consequences, such as learning, of naturally occurring plasticity in the brain. The song control system in the avian brain provides excellent opportunities for addressing such basic issues of behavioral neuroscience. Seasonal changes of environmental factors, such as photoperiod, have a profound effect on birds and most other animals. In songbirds seasonal changes in photoperiod elicit changes in circulating concentrations of gonadal steroid hormones, which in turn cause changes in song behavior and in morphological and physiological attributes of the neuroendocrine system that controls song. The exchange of social cues between individuals enhances the growth of the song system during the breeding season. The goal of this proposal is to use a comparative approach to explore the proximate mechanisms and behavioral functions of seasonal plasticity in the avian song control system. We will determine whether the social enhancement of the seasonal growth of the song nuclei is mediated by auditory stimuli. We will examine whether social stimulation from other birds enhances the growth of the song nuclei by increasing the recruitment and/or survival of newly generated neurons in the adult bird's song system. To test the hypothesis that maintenance of seasonally grown song nuclei depends on innervation from afferent nuclei, we will lesion nucleus HVc unilaterally in canaries that have been on breeding photoperiods for one month and compare the morphology of the afferent nuclei RA and Area X ipsilateral and contralateral to the lesion. The hypothesis that seasonal growth of the song nuclei is regulated by estrogenic metabolites of testosterone will be tested by measuring the morphology of song nuclei, song behavior, and plasma hormone levels in wild song sparrows implanted in early Fall with different steroids. We will use operant conditioning techniques to test the hypothesis that seasonal changes in song perception are functionally related to seasonal plasticity of the song system. The results of the proposed studies will increase our understanding of steroid hormonal and social influences on the nervous system, and of the relationship between plasticity in the adult brain and learning.