Topographic Maps and Visual Cortical Functions

地形图和视觉皮层功能

• 批准号: 7352031
• 负责人: Jianhua Cang
• 金额: $ 37.75万
• 依托单位: NORTHWESTERN UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-02-01 至 2012-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7352031
• 关键词: Affect; Axon; Behavior; Behavioral; Brain; Brain Injuries; Cues; Data; Discrimination; Disease; Disruption; Dorsal; Individual; Intervention; Knock-out; Knowledge; Lateral Geniculate Body; Left; Location; Maps; Measures; Molecular; Mus; Mutant Strains Mice; Nervous system structure; Neurons; Nicotinic Receptors; Nose; Output; Pattern; Physiological Processes; Process; Property; Research; Research Personnel; Retina; Retinal; Role; Sensory; Shapes; Structure; Swimming; Synapses; Testing; Visual; Visual Acuity; Visual Cortex; Visual system structure; Week; Whole-Cell Recordings; Wild Type Mouse; Work; area striata; behavior test; ganglion cell; genetic manipulation; orientation selectivity; postnatal; receptive field; relating to nervous system; research study; response; retinotopic; size; spatiotemporal; synaptic inhibition; visual information; visual process; visual processing

DESCRIPTION (provided by applicant): Retinotopic representation of visual space is a general feature of mammalian visual cortex. Experiments in this proposal will study whether the retinotopic map is required for the physiological processing of sensory information. Specifically, the proposed work will study the consequences that genetically disrupted retinotopic maps have for receptive field properties, cortical circuits and visual behaviors. Several lines of mutant mice that display mapping errors in their visual cortex will be used, including the mice deficient in the molecular guidance cues ephrin-As, the mice that have disrupted patterns of spontaneous activity in the developing retina, and the mice in which these two disruptive interventions are combined. In addition, retinotopic maps will also be disrupted in wild type mice by misexpressing ephrin-As in the developing visual cortex. Using these mice, the investigators will first determine whether cortical receptive fields are abnormal when retinotopic maps are disrupted. Single-unit recordings will be performed to measure the size, orientation selectivity and spatial tuning of individual cortical neurons. By comparing the receptive field properties of mice that have different degrees of mapping errors, the contribution of topographic maps in shaping receptive fields in the visual cortex will be determined. Second, intracellular whole cell recording will be performed in the intact brain to study the pattern of intracortical synaptic inhibition in the absence of a precise retinotopic map. Finally, using a swimming test of visual discrimination and a test of optomotor response, the investigators will determine whether disruption of retinotopic maps affects visual behaviors. Together, these studies will elucidate the role of retinotopic maps in visual processing and will also help define how precise patterns of synaptic connections contribute to the normal behavioral output of the nervous system in general. Importantly, these experiments will reveal how mis-wired visual systems function at cellular, circuit and behavioral levels. Such knowledge will be useful for the understanding and treatment of disorders resulting from brain injury and from aberrant neuronal connections.

描述（由申请人提供）：视觉空间的视网膜表示是哺乳动物视觉皮层的一般特征。该提案中的实验将研究感官信息的生理处理是否需要视网膜图。具体而言，拟议的工作将研究遗传破坏的视网膜图对接受田间特性，皮质电路和视觉行为的后果。将使用几条突变小鼠在其视觉皮层中显示映射误差的线，包括缺乏分子引导的小鼠以ephrin-as，ephrin-as是发育性视网膜中自发活性模式的小鼠，以及将这两种颠覆性干预措施的小鼠组合在一起。此外，通过在发育中的视觉皮层中将ephrin-as As misexpress-aps在野生型小鼠中也将破坏视网膜图。使用这些小鼠，研究人员将首先确定当破坏视网膜图时皮质接受场是否异常。将进行单单元记录，以测量单个皮质神经元的大小，方向选择性和空间调整。通过比较具有不同程度的映射误差的小鼠的接受场特性，将确定地形图在塑造视觉皮层中塑造接受场中的贡献。其次，在没有精确的视网膜图的情况下，将在完整的大脑中进行细胞内的全细胞记录，以研究皮质内突触抑制的模式。最后，使用视觉歧视的游泳测试和对验光反应的测试，研究人员将确定视网膜图的破坏是否会影响视觉行为。总之，这些研究将阐明视网膜图在视觉处理中的作用，还将有助于定义突触连接的精确模式，这通常有助于神经系统的正常行为输出。重要的是，这些实验将揭示失连的视觉系统如何在细胞，电路和行为水平上发挥作用。这种知识将有助于理解和治疗因脑损伤和异常神经元联系而导致的疾病。