FUNCTIONAL CONNECTIVITY IN PRIMARY VISUAL CORTEX

描述（由申请人提供）：在过去的几十年中，解剖学和生理学技术的结合已经生成了大脑内皮层和皮层下结构的主要连接的详细地图。挑战仍然是发现它们的功能。要理解一个主要联系的功能，需要通过有针对性的目标收集许多信息。该计划将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，重点关注两个主要问题：每种连接涉及哪些细胞类型？从它们产生的相关放电中估计出的连接强度是多少？首先，将进行实验以研究皮质和皮质丘脑连接是否遵循不同的布线策略（例如，所涉及的细胞类型，连接细胞之间的感受场匹配质量等）。其次，皮质、丘脑皮质和皮质丘脑连接的相对强度将通过测量这些连接中的每一个在输入和目标之间产生的相关放电来估计。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体同步中的作用（例如，视网膜内产生的同步、共享视网膜传入的膝状体细胞之间产生的同步、其他类型的同步）。所有这些问题将通过结合现代技术的同步记录和自动感受野映射与更经典的工具，如交叉相关分析，电微刺激和药理学可逆性失活的限制脑区。研究皮质-皮质和皮质-丘脑回路的特性对于理解视觉加工的神经机制具有重要意义。对这些机制的精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.