TECTOPULVINAR SYSTEM: MOTION DETECTION AND EVOLUTION

比较和演化研究表明，构造- 最古老的端脑上行通路的组成部分 并且对于运动检测的过程是至关重要的。加深对这一点的理解 系统可以阐明用于检测运动的视觉信息的处理， 方向在非哺乳动物，从而在哺乳动物中的这种处理的进化。 构造-足底系统可以看作是一系列的视觉信息 处理阶段：第一阶段处理视网膜：大概是简单的开/关细胞， 感受野极小;第二阶段处理-顶盖：高速运动 用顶盖神经元探测鸟类的中央灰层（SGC）， 直接接受视网膜的哺乳动物的浅灰色下层（SGSL） 在其独特的“瓶刷”树突状末端的输入;第三阶段处理- 丘脑：特定核团丘脑神经元的全局方向检测 鸟类的圆形核和哺乳动物的下枕核;以及IV期 处理─ 端脑：方向性的处理和视网膜病变的可能恢复。 本提案是为了研究运动检测的基板及其演化 鸡、鸽子和松鼠中的盖爪系统，使用免疫组织化学， 共聚焦显微镜，细胞内细胞填充和生理技术， 回答以下问题： 研究阶段II -运动检测细胞的SGC/SGSL的影响 非视网膜输入我们将检查来自峡核的输入， parabigemini，每一个来源的一个主要的胆碱能投射层上的 在鸟类和哺乳动物的瓶刷状树突末端，分别和各种 端脑输入什么是地形的相互连接的 顶盖和地峡胆碱能输入是否影响瓶刷的反应 树突末梢对视网膜刺激的反应 第三阶段的研究-方向性是如何从丘脑运动产生的 神经元？具体地说，SGC/SGSL神经元轴突如何终止于 圆肌/下枕？什么是三维形态 圆肌/下枕神经元 鸟类和哺乳动物？在松鼠的下枕中是否有 与鸟类圆形图中的分区相对应吗生理反应有哪些 松鼠下枕的早期

Comparative and evolutionary studies suggest that the tectopulvinar system is one of the most ancient components of the ascending pathways to the telencephalon and is vital to the process of motion detection. Improved understanding of this system may clarify the processing of visual information for detection of motion and direction in nonmammals and thus the evolution of such processing in mammals. The tectopulvinar system may be viewed as a series of visual information processing stages: Stage I processing-Retina: presumably simple On/Off cells with extremely small receptive fields; Stage II processing-Tectum: high speed motion detection by tectal neurons of the stratum griseum central (SGC) of birds and the lower stratum griseum superficiale (SGSL) of mammals in direct receipt of retinal inputs upon their unique "bottlebrush" dendritic endings; Stage III processing- Thalamus: global direction detection by specific thalamic neurons of the nucleus rotundus of birds and the nucleus inferior pulvinar in mammals; and Stage IV processing - Telencephalon: processing of directionality and possible restoration of retinotopy. This proposal is to study the substrate of motion detection and evolution of the tectopulvinar system in chicks, pigeons and squirrels, using immunohistochemistry, confocal microscopy, intracellular cell filling and physiological techniques to- answer the following questions: Studies of Stage II - Are motion detection cells of SGC/SGSL influenced by nonretinal inputs? We will examine the inputs from the nucleus isthmi and parabigemini, each the source of a major cholinergic projection upon the layer of bottlebrush dendritic endings in birds and mammals, respectively and of various telencephalic inputs. What is the topography of reciprocal connections of the tectum and the isthmi? Do cholinergic inputs influence the responses of bottlebrush dendritic endings to retinal stimulation? Studies of Stage III - How is directionality generated from motion by thalamic neurons? Specifically, how do SGC/SGSL neuronal axons terminate in the rotundus/inferior pulvinar? What is the three-dimensional morphology of rotundus/inferior pulvinar neurons in birds and mammals? Are there divisions in the inferior pulvinar of the squirrel that correspond to the divisions in the rotundus of birds? What are the physiological ro erties of the squirrel inferior pulvinar?