COMPARATIVE STUDIES OF VOCAL CONTROL

神经系统的一个基本特征是它们提供可塑性 结构和功能的变化，使动物能够适应 他们的环境。我们才刚刚开始了解潜在的 机制、限制和行为后果，例如 学习，大脑中自然产生的可塑性。这首歌 鸟类大脑中的控制系统提供了极好的机会 解决行为神经科学的这些基本问题。季节变化 环境因素，如光周期，对 鸟类和大多数其他动物。在鸣禽中的季节性变化 光周期引起性腺循环浓度的变化 类固醇激素，这反过来会导致歌曲行为和 神经内分泌系统的形态和生理特性 这就控制了歌曲。这项提案的目标是使用比较级的 探讨高血压性脑损伤的机制和行为功能 鸟类鸣叫控制系统中的季节性可塑性。的时间进程 歌声核团形态随季节变化的变化 光周期将在雄性金丝雀身上进行检测。放射自显影 技术将被用来确定气候的季节性变化是否 性腺类固醇激素的细胞积聚是性激素变化的基础 金丝雀宋核的形态。来检验这一假设 歌声核团的季节变化依赖于传入神经的支配 核，我们将单侧损毁金丝雀的HVC核并进行比较 传出核RA和X区同侧和同侧的形态 在暴露于繁殖光周期后，病变的对侧。 歌唱行为、荷尔蒙浓度和歌声核团将在 野生纳塔尔白冠麻雀在繁殖季节前后 来测试这个亚种的季节变化。用狂野的男歌 麻雀、歌唱行为、荷尔蒙浓度和歌声核团 在一年中的四个不同时间测量，以检验假设 歌曲制作的季节性变化与音乐的季节性可塑性相关 歌曲的核心。建议的研究结果将增加我们的 了解类固醇激素对神经系统的影响以及 成人大脑的可塑性与学习的关系。

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 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. The time course of changes in the morphology of song nuclei following changes in seasonal photoperiod will be examined in male canaries. Autoradiographic techniques will be used to determine whether seasonal changes in the cellular accumulation of gonadal steroid hormones underlie changes in the morphology of song nuclei in canaries. To test the hypothesis that seasonal changes in song nuclei depend on innervation from afferent nuclei, we will lesion nucleus HVC unilaterally in canaries and compare the morphology of the efferent nuclei RA and Area X ipsilateral and contralateral to the lesion following exposure to a breeding photoperiod. Song behavior, hormone concentrations, and song nuclei will be measured in wild Nuttal's white-crowned sparrows during and after the breeding season to test for seasonal changes in this subspecies. Using wild male song sparrows, song behavior, hormone concentrations, and song nuclei will be measured at four different times of year to test the hypothesis that seasonal changes in song production correlate with seasonal plasticity of the song nuclei. The results of the proposed studies will increase our understanding of steroid hormonal influences on the nervous system, and of the relationship between plasticity in the adult brain and learning.