Functional Organization of the Song Motor Control System

描述(由申请人提供)：鸟鸣是一种层次化的学习运动行为，由几乎连续连接的核心流控制。这条通路是双侧组织的，在每个半球都有解剖学上难以区分的结构。关于由这些结构编码的歌曲特征的性质或组织，人们知之甚少。在目前的方案中，我们使用一些免费的实验技术(单单位和多单位记录、刺激和损毁)来研究HVC中歌曲特征编码的组织，HVC是一个关键的端脑歌曲控制核团。这些研究将在正常和干扰的感觉反馈条件下，在会唱歌的成年斑马雀(斑点带绦虫)身上进行。 在目标1中，我们利用下丘脑SONG运动活动的半球间协调来研究运动前活动与SONG输出之间的关系。我们假设，对同时记录在两个半球的神经模式的分析将提供对歌曲特征的分层编码的洞察。我们认为，大脑半球的重合活动模式将指定关键的歌曲计时特征，如音节，可能还有音符、开头和偏置。感觉反馈的干扰会导致成年鸣禽歌唱输出的长期变化。目前尚不清楚这种干扰如何影响HVC中的歌曲运动前神经模式。目标2将比较在切断气管脊髓(TS)神经之前和之后HVC的神经活动模式，这是一种改变声音和本体感觉反馈的操作。我们将使用多单位记录来初步表征这种扰动对HVC群体响应的影响。然后，我们将使用单单位记录来识别受感觉反馈操作影响的神经细胞类型。 最后，AIM 3将研究HVC网络活动的扰动，无论是微损伤还是刺激，如何影响成年斑马雀正常的刻板印象的歌声输出。为了消除在完好的对侧HVC出现代偿活动的可能性，将对被迫用一个鸣唱系统半球歌唱的鸟类进行空间限制的操作。所提出的研究直接针对HVC中歌曲特征编码的时空组织。

DESCRIPTION (provided by applicant): Birdsong is a hierarchically patterned learned motor behavior controlled by a nearly serially connected stream of nuclei. This pathway is bilaterally organized, with anatomically indistinguishable structures in each hemisphere. Little is known regarding the nature, or organization, of song features that are encoded by these structures. In the present proposal, we use a number of complimentary experimental techniques (single- and multi-unit recording, stimulation and lesions) to investigate the organization of song feature encoding in HVc, a key telencephalic song control nucleus. These studies will be performed in singing adult zebra finches (Taeniopygia guttata) under normal and perturbed sensory feedback conditions. In AIM 1, we exploit interhemispheric coordination of song motor activity in HVc to study the relationship between premotor activity and song output. We hypothesize that analysis of neural patterns recorded simultaneously in both hemispheres will provide insight into the hierarchical encoding of song features. We propose that patterns of coincident activity across hemispheres will specify key song timing features such as syllable, and possibly note, onset and offset. Sensory feedback perturbations cause long-term changes in song output of adult songbirds. It is not known how such perturbations affect song premotor neural patterns in HVc. AIM 2 will compare neural activity patterns in HVc before and directly after cutting the tracheosyringeal (ts) nerve, a manipulation that alters both acoustic and proprioceptive feedback. We will use multiunit recording to initially characterize the effect of such perturbations on the HVc population response. We will then use single-unit recordings to identify neuronal cell types that are affected by sensory feedback manipulation. Finally, AIM 3 will investigate how perturbations of HVc network activity, either by microlesions or stimulation, affect the normally stereotyped song output of adult zebra finches. To eliminate the possibility of compensatory activity in the intact contralateral HVc, spatially restricted manipulations will be performed in birds forced to sing with only one song system hemisphere. The proposed studies directly address the spatial and temporal organization of song feature encoding in HVc.