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。 如果您要大声朗读这句话，您将在不到10秒钟内说出一个精确的，有序的50多种不同声音的顺序。 大脑如何存储单个语音的声音，然后如此迅速地以有意义的顺序协调这些声音的产生？ 关于钢琴家表演莫扎特奏鸣曲，鸟类的歌或昆虫的交配舞蹈，可能会问一个类似的问题。 大脑如何存储这些详尽的行为序列仍然未知。 使用鸣禽斑马雀科，一种模型有机体，可以学习有意义的声音序列，就像人类一样，跨学科研究团队将测试以下假设：大脑通过两个单独的机制编码和存储行为序列，这些机制是通过两种单独的机制进行操作的：一种编码机制的机制，用于voce声音和嗓音本身。 鉴于表现出详尽，有意义的行为序列的动物物种的多样性，这些发现将影响包括人类在内的各种生物体的理解。 该研究计划协调了来自四个不同学科（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中观察到的行为中的串行顺序包括学习将一组元素的手势单元组织成有目的的作用序列。成年雄性斑马雀（Taeniopygia guttata）产生了一个高度量化的行为序列序列（birdsong）的例子。 此外，已知前一位皮质区域（HVC，专有名称）编码合并的歌曲的合并前痕迹。尽管由类似的细胞类型组成，但假设HVC的内侧和侧向部分并行编码序列（内侧HVC）和音节（侧向HVC）。研究团队将测试歌曲的这两个维度是否是由1）中内侧和侧向HVC的生理差异编码的，还是2）内侧和侧向HVC的内在网络特性（或1和2的组合）。但是，行为中串行顺序的并行编码应为层次结构，在元素手势单位的痕迹上，序列处于监督位置。该团队还将测试是否会在声带皮层中以层次结构方式与外侧HVC发出的传出轴突相互作用。结果将阐明行为序列顺序的网络体系结构，并提供一个计算平台，以了解学习新序列如何塑造此类内存体系结构。