TECTOPULVINAR SYSTEM: MOTION DETECTION AND EVOLUTION

比较和进化研究表明，顶盖尺骨系统是 通往端脑的上升通道中最古老的组成部分 并且对运动检测过程至关重要。提高对这一点的理解 系统可以阐明用于检测运动的视觉信息的处理 在非哺乳动物中的方向，从而在哺乳动物中这种处理的进化。 顶盖尺骨系统可被视为一系列视觉信息 加工阶段：第一阶段加工-视网膜：可能是简单的开/关细胞 极小的感受野.第二阶段处理.顶盖：高速运动 鸟类灰质中央层(SGC)顶盖神经元的检测 哺乳动物视网膜灰质浅下层(SGSL)直接接受视网膜 它们独特的“瓶刷”树枝状末端的输入；第三阶段处理- 丘脑：特定核团丘脑神经元的全局方向检测 鸟类的圆核和哺乳动物的下枕核；以及IV期 正在处理- 端脑：方向性的处理和视网膜桥接的可能恢复。 本提案是为了研究运动检测的底物和进化 小鸡、鸽子和松鼠的顶盖尺骨系统，用免疫组织化学方法， 共聚焦显微镜、细胞内填充和生理技术- 回答以下问题： SGC/SGSL的II-Are运动检测细胞的研究 非视网膜输入？我们将检查来自峡核的输入和 Parabigemini，每个都是下丘脑层上主要胆碱能投射的来源 分别在鸟类和哺乳动物以及不同种类的鸟类和哺乳动物中的树枝状末端 端脑输入。两国相互联系的地形是什么？ 顶盖和峡部？胆碱能输入是否影响瓶刷的反应 视网膜刺激的树突末梢？ 阶段III的研究--丘脑如何通过运动产生方向性 神经元？具体地说，SGC/SGSL神经元轴突是如何在 圆锥/下枕骨？它的三维形态是什么？ 圆核/枕下神经元在脑内 鸟类和哺乳动物？松鼠的下枕骨有没有分节 与鸟类圆线的划分相对应吗？生理作用是什么？ 松鼠下枕骨的毛病？

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?