THALAMIC CONTROL OF CORTICAL VISUAL PROCESSING

中枢性视觉障碍的诊断和治疗进展 机制在很大程度上取决于对 视觉皮质的组织原则。的长远目标 这个项目是为了确定视觉的皮质机制是如何 通过丘脑输入控制。 在猫科动物中，有三个独立的信息通道来自眼睛和 以唯一的组合分布在 外侧膝状体和内侧膝状体组成的丘脑中继复合体 层间核(LGN-min)。LGN-MIN的层分布着它们的 输出到纹状体和纹外皮质的几个区域。建议数 研究的目的是：(I)阐明功能关系 这些层与其皮质目标之间的关系；(Ii)描述相互作用 在LGN-MIN层和皮质通路中；(Iii)确定 反应特性与皮质柱的相关性 层间电路。对于这些实验，将使用以下工具 单独或组合使用：(I)可逆失活 通过直接注射封闭剂进行单独的LGN-MIN细分； (2)表面对第17区颗粒上层的可逆失活 冷却；(3)通过冷却可逆地使区域17、18或19失活。 MIN对视觉的贡献的一个线索是它有一个证据 在暗视中的特定角色。最小值更大的假设 比LGN更灵敏的暗光将被直接测试。

Progress in the diagnosis and treatment of disorders of central visual mechanisms critically depends upon an understanding of the fundamental principles of organization of the visual cortex. The long-range goal of this project is to determine how cortical mechanisms of vision are controlled via thalamic inputs. In the cat, three separate channels of information originate in the eye and are distributed in unique combinations across the several layers of the thalamic relay complex composed of the lateral geniculate and medial interlaminar nuclei (LGN-MIN). The layers of the LGN-MIN distribute their outputs to striate and several areas of extrastriate cortex. The proposed research is designed to: (i) elucidate the functional relationships between these layers and their cortical targets; (ii) describe interactions among the LGN-MIN layers and corticocortical pathways; (iii) determine the dependence of response characteristics on the cortical column's interlaminar circuitry. For these experiments the following tools will be used, individually and in combination: (i) reversible inactivation of individual LGN-MIN subdivisions by direct injection of blocking agents; (ii) reversible inactivation of supragranular layers of area 17 by surface cooling; (iii) reversible inactivation of areas 17, 18 or 19 by cooling. A clue to the MIN's contribution to vision is evidence that it has a specific role in scotopic vision. The hypothesis that the MIN is more sensitive under dim-light than the LGN will be tested directly.