Neuronal mechanisms of multiplication and invariance

乘法和不变性的神经机制

• 批准号: 6898244
• 负责人: FABRIZIO GABBIANI
• 金额: $ 18.81万
• 依托单位: BAYLOR COLLEGE OF MEDICINE
• 依托单位国家: 美国
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-06-01 至 2007-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6898244
• 关键词: Orthoptera; afferent nerve; behavioral /social science research tag; biophysics; computational neuroscience; dendrites; dissection; electrophysiology; eye; morphology; motion perception; nerve threshold; neural information processing; neurophysiology; picrotoxin; sensorimotor system; sensory mechanism; space perception; stimulus /response; synapses; visual depth perception; visual fields; visual stimulus

DESCRIPTION:(provided by applicant) The long term objective of this research is to understand the biophysical mechanisms by which time varying sensory stimuli are integrated in individual neurons. The immediate goal is to provide detailed biophysical explanations of how individual neurons multiply two inputs and how they implement invariance to certain stimulus attributes. Multiplication has been implicated in many neural computations, like the extraction of motion information from visual images, in both vertebrate and invertebrate nervous systems. Invariance is an attribute commonly found in higher order neurons that respond selectively to a stimulus feature independently of its context. Currently, there is little understanding of how these computations are accomplished by neurons. These issues will be investigated in the visual system of the locust, which possesses a neuron, the lobula giant movement detector (LGMD), that responds to objects looming on a collision course towards the animal. This neuron implements a multiplication operation between two distinct inputs impinging on its dendrites and exhibits responses that are invariant to many attributes of the looming object. Many features of LGMD make it a favorable subject for biophysical studies. The specific aims of the project are to characterize the time-course of activation of the two inputs impinging on LGMD and their integration within its dendritic tree. Additionally, the anatomy of the cell, its intrinsic membrane properties and the geometry of the eye will be characterized and used to build a model of the cell and its response to looming stimuli. The techniques applied will include multielectrode recordings from presynaptic neurons to LGMD, intracellular recordings, pharmacological manipulations and compartmental modeling. The model and experimental data will be used to identify the biophysical mechanisms underlying multiplication and invariance in this neuron. Because similar computations are found in vertebrate central nervous systems, this project is expected to advance the general understanding of how multiplication and invariance are implemented for neural information processing.

描述：（由申请人提供） 这项研究的长期目标是了解生物物理 随时间变化的感觉刺激被整合到个体中的机制 神经元。近期目标是提供详细的生物物理学解释 单个神经元如何将两个输入相乘以及它们如何实现不变性 某些刺激属性。乘法与许多神经元相关 计算，例如从视觉图像中提取运动信息 脊椎动物和无脊椎动物的神经系统。不变性是一个属性 常见于对刺激有选择性反应的高阶神经元中 特征独立于其上下文。目前了解还很少 神经元如何完成这些计算。这些问题将会 在蝗虫的视觉系统中进行了研究，该系统拥有一个神经元 小叶巨型运动探测器（LGMD），对隐约可见的物体做出反应 朝向动物的碰撞路线。这个神经元实现了乘法 影响其树突和展品的两个不同输入之间的操作 对隐现物体的许多属性不变的响应。许多 LGMD 的特点使其成为生物物理学研究的热门课题。这 该项目的具体目标是描述激活的时间过程 影响 LGMD 的两个输入及其在树突中的整合 树。此外，细胞的解剖结构及其内在的膜特性 眼睛的几何形状将被表征并用于建立一个模型 细胞及其对迫在眉睫的刺激的反应。所应用的技术将 包括从突触前神经元到 LGMD 的多电极记录， 细胞内记录、药理学操作和区室 造型。模型和实验数据将用于识别 该神经元增殖和不变性的生物物理机制。 因为在脊椎动物中枢神经系统中也发现了类似的计算， 该项目预计将促进人们对如何 神经信息实现乘法和不变性 加工。