Organization and Function of Visual Cortical Feedback Systems

项目摘要 视觉感知是通过视网膜、视皮层和大脑皮质神经元之间的复杂相互作用来调节的。 皮质下的大脑结构。视觉对人类和其他灵长类动物的重要性反映在 大脑皮层中用于处理视觉信息的比例很大。因此，视觉上的缺陷 加工是特别衰弱的，不仅是眼睛的异常，皮质和大脑的异常也是如此。 皮质下回路。例如，儿童时期的斜视或弱视可能会对 处理视觉信息的大脑皮层回路。也有证据表明，某些形式的阅读障碍会导致 由中枢视觉系统异常引起。神经系统的功能依赖于复合体 由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。关于皮质反馈联系和皮质丘脑网络的一般原理 从老鼠视觉系统的研究中学到的知识可能也适用于调节认知的回路 功能，在自闭症和精神分裂症等疾病中可能受损。建议进行的研究包括 旨在揭示以下方面的组织和功能影响：1)皮质反馈连接到初级 视觉皮质；2)皮质-丘脑-皮质环路。这些研究是在老鼠身上进行的，以利用 分子、遗传和病毒工具的范围可用于阐明大脑回路并将它们与 使用光遗传和成像方法来实现其功能。这四个目标将揭示：1)反馈的功能影响 从皮质区域AL和PM的第2/3层或第5层到V1；2)第2/3层或第5层的反馈 大脑皮层AL区和PM至V1区与V1内特定的抑制回路整合；3)输入-输出 丘脑枕核投射到已识别的视觉皮质区域的神经元之间的关系；4) 枕骨输入对视觉皮质的功能影响。

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.