SPATIAL CHARACTERISTICS OF NEURONS IN THE STRIATE CORTEX

纹状皮层神经元的空间特征

• 批准号: 3258217
• 负责人: ALFRED B BONDS
• 金额: $ 9.72万
• 依托单位: VANDERBILT UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1980
• 资助国家: 美国
• 起止时间: 1980-09-30 至 1989-09-29
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3258217
• 关键词: evoked potentials; eye disorder diagnosis; neural information processing; neurons; neurophysiology; occipital lobe /cortex; psychophysics; retinal adaptation; single cell analysis; vision; visual cortex; visual feedback; visual pathways; visual stimulus

The research will examine the mechanisms that support spatial discrimination (specifically, orientation selectivity) in single striate cortical neurons and correlate physiological characteristics at a specific recording site with intracortical connectivity at that same site. The goal is to produce a comprehensive model of striate cortex that integrates structure and function. Single neurons in the retina and lateral geniculate nucleus dissect a visual scene with respect to location in space and spatial frequency (periodicity of repeating patterns). Striate cortical neurons add selectivity for boundary orientation and direction of motion; the physiological mechanisms that support such selectivity are as yet poorly understood. Two existing hypotheses suggest that selectivity is based primarily either on excitation or inhibition. This laboratory has developed a method that uses two grating stimuli simultaneously presented to separate excitatory and inhibitory influences. Orientation selectivity was found to be the result of three different processes combined in different degree across the total cell population. Recent progress in tracing connectivity in the striate cortex would predict that the relative importance of each process would vary systematically with the laminar location of the recorded cell. This experimental program has four primary objectives: (1) Correlation of the organization of orientation selectivity in a given cell with its laminar location, which will help to position the cell in the processing hierarchy in striate cortex; (2) Verification of the double grating method of separating excitation and inhibition by blocking inhibition pharmacologically to reveal the isolated excitatory input to the cell; (3) More detailed study of the inhibitory mechanisms resolved through double-grating tests, with the intent of testing one mechanism for possible identity with the cortical gain control described by others; (4) Tracing intracortical connectivity at specific recording sites through local injection of a retrogradely transported tracing agent (HRP), which will help to establish the microcircuitry responsible for known electrophysiological characteristics.

该研究将检查支持空间的机制 单个条纹中的歧视（特别是方向选择性） 皮质神经元和特定的生理特征相关 在同一站点录制具有皮质内连通性的位置。 目标 是为了产生整合的横纹皮质模型 结构和功能。 视网膜和侧向核中的单神经元解剖A 关于空间和空间频率位置的视觉场景 （重复模式的周期性）。 条纹皮质神经元添加 边界方向和运动方向的选择性；这 支持这种选择性的生理机制尚未 理解。 两个现有的假设表明选择性是基于的 主要是激发或抑制。 这个实验室有 开发了一种同时呈现的两个光栅刺激的方法 分开兴奋性和抑制性影响。 方向选择性 被发现是三个不同过程的结果 整个细胞种群的不同程度。 最近的进展 跟踪条纹皮层中的连通性将预测相对 每个过程的重要性随层流的系统变化 记录的单元格的位置。 该实验计划有四个主要目标：（1） 在给定单元格中的定向选择性的组织 层流位置，这将有助于将电池定位在处理中 条纹皮质的层次结构； （2）双光栅方法的验证 通过阻止抑制来分离激发和抑制 在药理上揭示了细胞的孤立兴奋性输入； （3） 对通过的抑制机制进行了更详细的研究 双颗粒测试，目的是测试一种机制 与他人描述的皮质增益控制的身份； （4）跟踪 通过本地的特定记录站点的皮质内连通性 注入逆转运输的跟踪剂（HRP），该剂将 帮助建立负责已知的微电路 电生理特征。