Organization and Function of Visual Cortical Feedback Systems

项目摘要 视觉感知是由视网膜、视皮层和视皮层中的神经元之间的复杂相互作用介导的。 大脑皮层下结构视觉对人类和其他灵长类动物的重要性反映在 大脑皮层中有很大一部分专门处理视觉信息。因此，视觉缺陷 处理是特别衰弱和引起的异常不仅在眼睛，而且在皮层和 皮层下回路例如，儿童时期的斜视或弱视会对儿童的视力产生长期影响。 处理视觉信息的皮层回路也有证据表明，某些形式的诵读困难导致 中枢视觉系统异常神经系统的功能依赖于复杂的 由跨多个皮层的多种神经元类型组成的神经元网络之间的相互作用， 皮质下区域。关于皮质反馈连接和皮质丘脑网络的一般原则 从老鼠视觉系统的研究中了解到的信息可能也适用于介导认知功能的回路。 功能，并可能在自闭症和精神分裂症等疾病中受损。拟议的研究是 旨在揭示组织和功能的影响：1）皮层反馈连接的主要 视皮层; 2）皮层-丘脑-皮层回路。这些研究是在老鼠身上进行的， 一系列分子、遗传和病毒工具，可用于阐明大脑回路并将其与 使用光遗传学和成像方法。这四个目标将揭示：1）反馈的功能影响 从皮层区AL和PM的层2/3或层5到V1; 2）从皮层区AL和PM的层2/3或层5到V1的反馈如何 皮层区AL和PM至V1与V1内的特定抑制回路整合; 3）输入-输出 丘脑枕核中投射到已识别的视觉皮层区域的神经元的关系; 4） 枕输入对视觉皮层的功能影响。

Project Summary Visual perception is mediated by complex interactions amongst neurons in the retina, visual cortex, and subcortical brain structures. The importance of vision to humans and other primates is reflected in the enormous percentage of cerebral cortex devoted to processing visual information. Thus, deficits in visual processing are particularly debilitating and arise from abnormalities not only in the eye, but also in cortical and subcortical circuitry. For example, strabismus or amblyopia during childhood can have long-lasting effects on the cortical circuits that process visual information. There is also evidence that some forms of dyslexia result from central visual system abnormalities. The function of the nervous system is dependent on complex interactions between networks of neurons composed of multiple neuron types across multiple cortical and subcortical areas. General principles about cortical feedback connections and corticothalamic networks learned from studies of the mouse visual system are likely to also apply to circuits mediating cognitive functions and may be impaired in disorders such as autism and schizophrenia. The proposed studies are aimed at revealing the organization and functional impact of: 1) cortical feedback connections to the primary visual cortex; and 2) cortico-thalamo-cortical circuits. These studies are conducted in mice to take advantage of the range of molecular, genetic, and viral tools that can be used to elucidate brain circuits and link them to function using optogenetic and imaging methods. The 4 aims will reveal: 1) the functional impact of feedback from layers 2/3 or layer 5 of cortical areas AL and PM to V1; 2) how feedback from layers 2/3 or layer 5 of cortical areas AL and PM to V1 integrate with specific inhibitory circuits within V1; 3) the input-output relationships of neurons in the pulvinar nucleus of the thalamus that project to identified visual cortical areas; 4) the functional impact of pulvinar inputs to the visual cortex.