Parallel Encoding of Sequence and Structure in a Motor Memory Trace

运动记忆轨迹中序列和结构的并行编码

• 批准号: 1456965
• 负责人: James Johnson
• 金额: $ 52.06万
• 依托单位: Florida State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-08-01 至 2020-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1456965&HistoricalAwards=false
• 关键词: Parallel; Encoding; Sequence; Structure; Motor

The purpose of this project is to elucidate how serial order is coded by the brain. If you were to read this sentence aloud, you would utter a precise, ordered sequence of over 50 distinct vocal sounds in less than 10 seconds. How does the brain store the individual sounds of speech and then coordinate the production of these sounds in a meaningful order so quickly? A similar question could be asked about the pianist performing a Mozart sonata, the songs of birds, or the mating dances of insects. How the brain stores these elaborate sequences of behavior remains unknown. Using the songbird zebra finch, a model organism that learns meaningful sequences of vocal sounds like humans do, the interdisciplinary research team will test the hypothesis that the brain encodes and stores sequences of behavior through two separate mechanisms that operate in parallel: one coding mechanism for the sequence of vocal sounds and one for the vocal sounds themselves. Given the diversity of animal species that display elaborate, meaningful sequences of behavior, the findings will influence understanding across a broad array of organisms, including humans. The research plan coordinates the activity of a faculty research team from four different disciplines (Neuroanatomy, Neurophysiology, Mathematics, and Statistics) and will provide students with a unique interdisciplinary training opportunity and environment. Observed in nearly all animal forms (and exemplified by human speech) serial order in behavior consists of learning to organize a set of elemental gestural units into a purposeful sequence of action. Adult male zebra finches (Taeniopygia guttata) produce a highly quantifiable example of serial order in behavior (birdsong). Moreover, a premotor cortical region (HVC, proper name) is known to encode a consolidated premotor trace of song. Although consisting of similar cell types, the medial and lateral portions of HVC are hypothesized to encode the sequence (medial HVC) and syllables (lateral HVC) of song in parallel. The research team will test whether these two dimensions of song are encoded by physiological differences in 1) afferent input to medial and lateral HVC, or 2) the intrinsic network properties of medial and lateral HVC (or a combination of 1 and 2). However, parallel encoding of serial order in behavior should be hierarchical, with traces for sequence in a supervisory position over traces for elemental gestural units. The team will also test whether efferent axons emanating from medial and lateral HVC interact in a hierarchical fashion within vocal-motor cortex. Results will elucidate a network architecture for serial order in behavior and provide a computational platform to understand how learning new sequences shapes such memory architectures.

该项目的目的是阐明大脑如何编码串行顺序。 如果您大声朗读这句话，您将在不到 10 秒的时间内发出由 50 多种不同声音组成的精确、有序的序列。 大脑如何存储单个语音，然后如此快速地以有意义的顺序协调这些声音的产生？ 关于钢琴家演奏莫扎特奏鸣曲、鸟儿的歌声或昆虫的交配舞蹈，也可以提出类似的问题。 大脑如何存储这些复杂的行为序列仍然未知。 跨学科研究小组将使用鸣鸟斑胸草雀（一种像人类一样学习有意义的声音序列的模式生物）来测试这样的假设：大脑通过两种并行运行的独立机制来编码和存储行为序列：一种编码机制声音序列和声音本身的序列。 鉴于动物物种的多样性，它们表现出复杂、有意义的行为序列，这些发现将影响对包括人类在内的广泛生物体的理解。 该研究计划协调来自四个不同学科（神经解剖学、神经生理学、数学和统计学）的教师研究团队的活动，并将为学生提供独特的跨学科培训机会和环境。 在几乎所有动物形式（并以人类语言为例）中观察到的行为的序列顺序包括学习将一组基本手势单元组织成有目的的动作序列。成年雄性斑胸草雀（Taeniopygia guttata）产生了高度可量化的序列行为（鸟鸣）的例子。 此外，已知运动前皮质区域（HVC，专有名称）可以编码歌曲的巩固运动前轨迹。尽管由相似的细胞类型组成，但 HVC 的内侧和外侧部分被假设为并行编码歌曲的序列（内侧 HVC）和音节（外侧 HVC）。研究小组将测试歌曲的这两个维度是否由以下生理差异编码：1）内侧和外侧 HVC 的传入输入，或 2）内侧和外侧 HVC 的内在网络特性（或 1 和 2 的组合）。然而，行为中串行顺序的并行编码应该是分层的，序列轨迹位于基本手势单元轨迹之上的监督位置。该团队还将测试从内侧和外侧 HVC 发出的传出轴突是否在发声运动皮层内以分层方式相互作用。结果将阐明行为串行顺序的网络架构，并提供一个计算平台来理解学习新序列如何塑造这种记忆架构。