Investigating the spatial representation and plasticity rules of a cortically dri

描述（由申请人提供）：人类有能力学习和执行广泛的复杂运动行为，这些行为是日常生活中不可或缺的，从弹钢琴到说话，但对这些行为如何在大脑中表现知之甚少。许多跨物种的研究试图阐明前脑运动中心的电路组织，但用于解决这个问题的行为范围仅限于先天和相对简单的运动。 鸣禽提供了一个很好的实验模型，以研究组织的确定皮层电路的基础上，一个复杂的学习运动行为。鸣禽大脑中不同的运动区域已经被确定，它们在歌曲产生中起着重要作用。其中一个区域是HVC核（专有名称），它被证明是歌曲运动序列产生的部位。HVC中的前运动神经元在歌唱过程中很少放电，在每次演唱歌曲的单一精确时刻表现出短暂的动作电位爆发。不同的神经元在歌曲中的不同时间爆发，这表明这些神经元形成了对时间的稀疏表示。虽然据估计，在歌曲的任何时刻，大约有200个神经元同时活跃，但实际上，我们对这种运动前神经元网络在大脑中的组织方式以及这种组织所固有的可塑性水平一无所知。 的两个具体 本提案中讨论的目标旨在解决这些问题。使用双光子显微镜可视化的HVC神经元在体内的网络，我们将调查的歌曲电路的时空组织和进行纵向研究的歌曲相关的活动。特别地，目标1将解决是否存在用于歌曲表演的通用运动图，使得核的特定区域中的细胞与类似的时间相关。 一群个体的属性。它还将确定个体内的相邻神经元是否基于其时间属性形成集群。目标2将测试这些前运动神经元的时间特性是否随时间推移而变化，以及网络固有的可塑性程度。 这些实验将是第一个研究大脑中控制熟练运动行为的空间表征的规则，以及这种运动前网络随时间变化的程度。

DESCRIPTION (provided by applicant): Humans have the ability to learn and execute a wide range of complex motor behaviors that are integral to everyday life, from playing the piano to speaking, but little is known about how these behaviors are represented within the brain. A number of studies across species have attempted to elucidate the circuit organization of forebrain motor centers, but the range of behaviors used to address this issue has been limited to innate and relatively simple movements. Songbirds offer an excellent experimental model to study the organization of identified cortical circuits underlying a complex learned motor behavior. Distinct motor regions of the songbird brain have been identified that play an essential role in song production. One of these areas is the nucleus HVC (proper name), which has been shown to be the site of motor sequence generation for the song. Premotor neurons in HVC fire very sparely during singing, exhibiting a short burst of action potentials at a single precise moment within each rendition of the song. Different neurons burst at different times in the song, suggesting that these neurons form a sparse representation of time. Although it has been estimated that a group of approximately 200 neurons are simultaneously active at any moment during the song, practically nothing is known of how this network of premotor neurons is organized in the brain and the level of plasticity inherent in this organization. The two specific aims discussed in this proposal seek to address these issues. Using two-photon microscopy to visualize the network of HVC neurons in vivo, we will investigate the spatiotemporal organization of the song circuit and conduct a longitudinal study of song-related activity. In particular, Aim 1 will address whether there is a universal motor map for song performance, such that cells in specific regions of the nucleus are invariantly associated with similar temporal properties across a population of individuals. It will also determine whether neighboring neurons within an individual form clusters based on their temporal properties. Aim 2 will test whether the temporal properties of these premotor neurons shift over time, and the degree of plasticity inherent in the network. These experiments will be the first to examine the rules governing the spatial representation of a skilled motor behavior in the brain and the extent to which this premotor network changes over time.