FUNCTIONAL CONNECTIVITY IN PRIMARY VISUAL CORTEX

描述(申请人提供)：在过去的几十年里，解剖学和生理学技术的结合已经生成了大脑内皮质和皮质下结构所建立的主要连接的详细地图。挑战仍然是发现它们的功能。理解主要联系的功能需要通过有针对性的目标收集许多信息。这项提案将通过关注两个主要问题来研究视觉通路中两种主要类型的连接(皮质和皮质丘脑)的特性：每种连接涉及的细胞类型是什么？根据它们产生的相关触发来估计连接的强度有多大？首先，将进行实验以调查皮质和皮质丘脑的连接是否遵循不同的连接策略(例如，所涉及的细胞类型、连接的细胞之间的感受野匹配的质量等)。其次，皮质、丘脑和丘脑连接的相对强度将通过测量每种连接产生的输入和目标之间的相关放电来估计。第三，将进行实验，以研究皮质丘脑通路在调节不同类型的膝状同步性中的作用(例如，在视网膜内产生的同步，在共享视网膜传入的膝状细胞之间产生的同步，以及其他类型的同步)。所有这些问题将通过将现代同步记录和自动感受野映射技术与更经典的工具相结合来解决，如互相关分析、电微刺激和限制脑区的药物可逆失活。研究皮质和皮质丘脑回路的特性对于理解视觉处理的神经机制很重要。对这些机制的准确了解最终可能有助于预防和治疗不同形式的视觉障碍。

DESCRIPTION (provided by applicant): Over the past decades, the combination of anatomical and physiological techniques has generated a detailed map of the main connections made by cortical and subcortical structures within the brain. The challenge remains to discover their function. Understanding the function of a major connection requires collecting many pieces of information through well-targeted objectives. This proposal will study the properties of two major types of connections within the visual pathway (corticocortical and corticothalamic) by focusing on two main questions: What cell types are involved in each connection? What is the strength of the connections as estimated from the correlated firing they generate? First, experiments will be done to investigate whether corticocortical and corticothalamic connections follow different wiring strategies (e.g. cell types involved, quality of the receptive-field match between connected cells, etc.). Second, the relative strength of corticortical, thalamocortical and corticothalamic connections will be estimated by measuring the correlated firing generated between inputs and targets by each of these connections. Third, experiments will be done to investigate the role of the corticothalamic pathway in modulating different types of geniculate synchrony (e.g. synchrony generated within the retina, synchrony generated among geniculate cells that share a retinal afferent, other types of synchrony). All these questions will be addressed by combining modern techniques of simultaneous recordings and automatic receptive field mapping with more classical tools such as cross-correlation analysis, electrical microstimulation and pharmacological reversible inactivation of restricted brain regions. The study of the properties of corticocortical and corticothalamic circuits is important to understand neural mechanisms involved in visual processing. A precise knowledge of these mechanisms could eventually help to prevent and treat different forms of visual disorders.