Neuronal Mechanisms of Motor Exploration and the Emergence of Structured Behavior

运动探索的神经机制和结构化行为的出现

基本信息

批准号：
8907994
负责人：
MICHALE S FEE
金额：
$ 31.73万
依托单位：
MASSACHUSETTS INSTITUTE OF TECHNOLOGY
依托单位国家：
美国
项目类别：
财政年份：
2008
资助国家：
美国
起止时间：
2008-04-01 至 2016-06-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8907994
关键词：
Acoustics Address Adolescent Adult Appearance Area Basal Ganglia Behavior Behavioral Bilateral Biological Models Birds Brain Brain Diseases Cell Nucleus Cognitive Complex Data Development Developmental Delay Disorders Exhibits Exploratory Behavior Feedback Funding Generations Health Human Individual Lesion Link Mammals Modeling Motor Motor Cortex Movement Neurons Parents Pathway interactions Periodicity Plastics Process Production Prosencephalon Relative (related person)Role Schizophrenia Signal Transduction Songbirds Speech Staging Stereotyping Structure Testing Thalamic Nuclei Thalamic structure Time Work design developmental disease emerging adult learned behavior motor control neural circuit neurodevelopment neurophysiology prevent relating to nervous system research study sound stereotypy vocal learning vocalization young adult zebra finch

项目摘要

DESCRIPTION (provided by applicant): The songbird has emerged as a powerful model system in which to pursue a mechanistic, neural circuits-level understanding of the development of complex sequential behaviors. Songbirds acquire their songs through a process reminiscent of speech acquisition in humans, modeling their vocalizations on the songs of their parents. They begin by singing a highly variable unstructured sequence of sounds, called subsong, which is like early babbling in humans. Gradually, their vocalizations acquire a single rhythmically repeated 'protosyllable', similar to canonical babbling in humans ('bababa'), which is then followed by a differentiation of sounds into multiple distinct syllables that will comprise their adult song. The finished product is a stereotyped sequence of sounds that is driven by a set of forebrain premotor nuclei analogous to motor cortex. The process of motor exploration, followed by the gradual emergence and refinement of precise temporally structured behavior, is the basic framework by which all complex behaviors are learned. In our previous studies, we have shown that subsong vocalizations are not simply the product of an 'immature' motor cortex, but are produced by a separate cortical circuit (a 'variability-generating circuit') dedicaed to the production of exploratory vocal variability. In preliminary experiments, we have shown that the earliest stereotyped components of juvenile song (protosyllables) are generated by rhythmic stereotyped activity in the same part of motor cortex that eventually produces adult song (the 'sequence- generating circuit'). The first specific aim of this proposal builds on earlier work to fully characterize the development of neural activity in the sequence-generating circuit and its relation to milestones in vocal learning. We have also found that the emerging stereotyped activity motor cortex is highly synchronized with the ongoing babbling vocalizations. In other words, the sculpting of syllables from babbling appears to require an intricate coordination between the variability- and sequence-generating circuits. Thus, the second two aims of this proposal are focused on characterizing signals in the thalamic and cortical pathways that link these two circuits. In summary, we have begun to understand, at a detailed mechanistic level, how sequence- generating circuits in motor cortex begin to sculpt adult-like behaviors out of the exploratory movements produced by separate variability-generating circuits. Given the homology between avian and mammalian forebrain circuitry, such an understanding could have profound implications for identifying underlying causes, at the circuit level, of human developmental disorders in both motor and cognitive domains.

描述（由申请人提供）：鸣禽已成为一种强大的模型系统，在其中追求机械性的，神经回路级别对复杂顺序行为的发展的理解。鸣禽通过一个让人联想到人类语音获取的过程来获得他们的歌曲，对他们父母的歌曲进行了轰动。他们首先唱出一个高度可变的非结构化声音序列，称为subsong，就像在人类中的早期胡言乱语一样。逐渐地，他们的发声获得了一种节奏的重复的“原始人”，类似于人类中的规范bablbling（“ bababa”），然后随后将声音的分化分为多个不同的音节他们的成人歌。成品是陈规定型的声音序列，由一组类似于运动皮层的前脑前核核驱动。运动勘探的过程，然后是精确的时间结构化行为的逐渐出现和完善的过程，是学习所有复杂行为的基本框架。在我们先前的研究中，我们已经表明，子谐声不仅是“未成熟”运动皮层的产物，而且是由单独的皮质电路（一种“可变性生成电路”）产生的，该电路专用于产生探索性人声性。在初步实验中，我们表明，最早的刻板印象成分（Protosyllables）是由节奏的刻板印象在运动皮层的同一部分产生的，最终会产生成人歌曲（“序列生成电路”）。该提案的第一个具体目的是建立在早期工作的基础上，以充分表征序列生成电路中神经活动的发展及其与声带学习中的里程碑的关系。我们还发现，新兴的定型活动运动皮层与正在进行的babling发声高度同步。换句话说，从巴布尔（Babbling）雕刻音节似乎需要在变异性和序列产生电路之间进行复杂的协调。因此，该提案的第二个目标集中在表征将这两个电路连接的丘脑和皮质途径中的信号。总而言之，我们已经开始从详细的机械级别上理解运动皮层中的序列产生电路如何开始从单独的变异产生电路产生的探索性运动中塑造出类似成人的行为。鉴于禽和哺乳动物前脑回路之间的同源性，这种理解可能对识别电路和运动领域中人类发育障碍的潜在原因具有深远的影响。