Synaptic processing in the basal ganglia

描述（申请人提供）：鸣禽的声乐学习是人类声乐学习的一种独特的，实验可获得的模型，也体现了使用感觉反馈的运动学习的一般过程。雄性鸣禽通过首先记住父亲的歌声来学习求爱的歌声，然后用听觉反馈来匹配自己的歌声和父亲的歌声。这个模型系统的一个主要优点是存在独立的前脑回路，参与产生歌曲和学习歌曲。所谓的“前前脑通路”对声乐学习至关重要，最近发现它与哺乳动物基底神经节通路有很大的相似之处，而基底神经节通路已知参与运动控制和运动学习。具体来说，一般回路的连通性、使用的神经递质和存在的神经元种类，与鸟类和哺乳动物基底神经节中信息处理的基本回路相同的假设是一致的。本文提出的实验将使用电生理学和形态学方法来测试前脑通路的关键微电路是否支持这一观点。此外，实验将测试多巴胺在前脑通路中的神经调节作用是否与哺乳动物相似。这些实验将为了解鸟类前脑通路的工作原理提供必要的信息。如果这些假设得到支持，两个主要的好处将随之而来。首先，鸟类鸣叫系统的工作将会加速，因为它可以利用哺乳动物已有的丰富信息来指导。此外，鸣叫系统具有经过充分研究的自然学习行为的优点，将被验证为比迄今为止实现的更直接适用于哺乳动物基底神经节功能的模型系统。这种理解基底神经节的补充方法是有价值的，因为研究基底神经节疾病，如帕金森病和亨廷顿病，可能需要对基底神经节的信息处理有基本的了解。

DESCRIPTION (provided by applicant): Vocal learning in songbirds is a unique, experimentally accessible model of human vocal learning that also exemplifies the general process of motor learning using sensory feedback. A male songbird learns his courtship song by first memorizing his father's song, and later using auditory feedback to match his own song to his memory of his father's song. One major advantage to this model system is the existence of separate forebrain circuits involved in producing the song and in learning it. The so-called "anterior forebrain pathway", which is essential for vocal learning, has recently been found to bear gross similarities to the mammalian basal ganglia pathway, which is known to be involved in motor control and motor learning. Specifically, the general circuit connectivity, neurotransmitters used, and neuron classes present, are consistent with the hypothesis that the same basic circuitry underlies information processing in avian and mammalian basal ganglia. The experiments proposed here will use electrophysiological and morphological approaches to test whether key microcircuitry of the anterior forebrain pathway supports this view. In addition, the experiments will test whether neuromodulatory actions of dopamine in the anterior forebrain pathway are similar to those in mammals. These experiments will provide necessary information about how the avian anterior forebrain pathway works. If the hypotheses are supported, two major benefits will ensue. First, work on the avian song system will accelerate because it can be guided by the wealth of information already available for mammals. Moreover, the song system, with its advantages of a well-studied, naturally-learned behavior, will be validated as a more directly applicable model system of mammalian basal ganglia function than heretofore realized. Such complementary approaches to understanding the basal ganglia are valuable because approaches to disorders of the basal ganglia such as Parkinson's and Huntington's diseases will likely require fundamental understanding of information processing in the basal ganglia.