THALAMIC CONTROL OF CORTICAL VISUAL PROCESSING

中枢性视觉障碍的诊治进展 关键取决于对基本原理的理解 视觉皮层的组织原理。 长期目标是 这个项目是为了确定视觉的皮层机制是如何 通过丘脑输入控制。 在猫的眼睛里，有三个独立的信息通道， 以独特的组合分布在几个层之间， 由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的层分布其 输出到纹状体和纹外皮质的几个区域。 拟议 研究的目的是：（一）阐明功能关系 这些层和他们的皮质目标之间;（ii）描述相互作用 在LGN-MIN层和皮质皮质通路之间;（iii）确定 反应特性对皮质柱的依赖性 层间电路 对于这些实验，将使用以下工具 单独和组合使用：（i）可逆失活 通过直接注射封闭剂进行单独的LGN-MIN细分; (ii)表面对17区颗粒上层的可逆失活 冷却;（iii）通过冷却使区域17、18或19可逆失活。 MIN对视力的贡献的一个线索是它具有一个 在暗视觉中的特殊作用。 假设最小值大于 在昏暗的光线下比LGN敏感，将直接测试。

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.