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：（申请人提供） 这项研究的长期目标是了解生物物理 机制随着时间的变化，感觉刺激被整合到个人 神经元。直接目标是提供详细的生物物理解释 单个神经元如何乘以两个输入以及它们如何实施不变性 某些刺激属性。乘法已与许多神经有关 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神经系统。不变性是一个属性 通常以高阶神经元对刺激反应的高阶神经元发现 特征独立于其上下文。目前，几乎没有理解 这些计算是如何通过神经元完成的。这些问题将是 在具有神经元的蝗虫的视觉系统中进行了调查， 小叶巨型运动检测器（LGMD），响应于迫在眉睫的物体 对动物的碰撞过程。该神经元实现繁殖 在两个不同的输入之间撞击其树突和展品之间的操作 对迫在眉睫的对象的许多属性不变的响应。许多 LGMD的特征使其成为生物物理研究的有利主题。这 该项目的具体目的是表征激活的时间顺序 在撞击LGMD及其在树突中的两个输入中 树。此外，细胞的解剖结构，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。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，药理学操纵和隔室 造型。模型和实验数据将用于确定 该神经元中繁殖和不变性的生物物理机制。 由于在脊椎动物中枢神经系统中发现了类似的计算，所以 预计该项目将提高人们对如何 实施乘法和不变性以进行神经信息 加工。