STRUCTURAL ORGANIZATION OF THE SUPERIOR COLLICULUS

上丘的结构组织

• 批准号: 3265455
• 负责人: WILLIAM Charles HALL
• 金额: $ 17.49万
• 依托单位: DUKE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1989
• 资助国家: 美国
• 起止时间: 1989-08-01 至 1994-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3265455
• 关键词: acetylcholine; cats; electron microscopy; eye movements; gamma aminobutyrate; immunocytochemistry; inhibitor /antagonist; innervation; neural information processing; neuroanatomy; neurotransmitters; parasympathetic nervous system; saccades; sensorimotor system; stimulant /agonist; substantia nigra; superior colliculus; synapses; tegmentum; thalamus

The study of the cell populations that control gaze has contributed greatly to our understanding of sensorimotor integration in the vertebrate brain. The long term goal of the proposed research is to increase understanding of the neural control of gaze by studying synaptic relationships within the intermediate grey layer of the superior colliculus, an area whose central role in gaze mechanisms is well-established. The intermediate grey layer contains cells which are premotor in the sense that they respond before saccadic eye movements and send axons, by way of a pathway called the predorsal bundle, to the lower brainstem gaze centers. These brainstem centers, in turn, project to the motor neurons that are involved in shifts in gaze. For understanding the mechanisms of sensorimotor integration in the intermediate grey layer, it is essential to characterize the inputs responsible for the responses of the predorsal bundle cells. Previous studies have shown that the intermediate grey layer is heavily innervated by fibers that utilize the neurotransmitters gamma- aminobutryic acid (GABA) and acteylcholine. The proposed experiments examine the relationships between these two fiber systems and the predorsal bundle cells in the cat. The experiments test the hypothesis that zone incerta, a nucleus located in the ventral thalamus, is an important source of the GABA ergic input to these cells. They also test the idea that a population of cells in the reticular formation, the pedunculopontine tegmental nucleus, is a cholinergic relay between the output of the basal ganglia and the predorsal bundle cells. Specifically, these experiments are designed: 1. To locate, using retrograde axonal transport methods, the cells of origin of the incertotectal pathway and to determine, by using a combination of retrograde tracing and immunocytochemical methods, whether zona incerta is a source of GABAergic input to the intermediate grey layer. 2. To characterize the ultrastructural features and postsynaptic targets of the incertotectal terminations in the intermediate grey layer and to examine whether those terminations directly contact predorsal bundle cells, by using a combination of anterograde and retrograde tracing methods in tissue prepared for electron microscopy. 3. To determine, using a combination of anterograde and retrograde methods in tissue prepared for electron microscopy, whether the cholinergic cells in the pedunculopotine tegmental nucleus receive input from substantia nigra pars reticulata, one of the efferent nuclei of the basal ganglia. 4. To characterize the postsynaptic target(s) of the cholinergic projection from the pedunculopotine tegmental nucleus to the intermediate grey layer, and to examine whether the cholinergic terminals contact predorsal bundle cells, by using a combination of anterograde, retrograde and immunocytochemical methods in tissue prepared for electron microscopy.

对控制凝视的细胞群的研究做出了贡献 极大地促进了我们对感觉运动整合的理解 脊椎动物的大脑。 拟议研究的长期目标是 通过研究增加对凝视神经控制的理解 中间灰层内的突触关系 上丘，在凝视机制中发挥核心作用的区域 完善的。 中间灰色层包含以下细胞： 前运动是指它们在眼球扫视运动之前做出反应 并通过称为前背束的途径将轴突发送到 脑干凝视中心较低。 这些脑干中心反过来投射 涉及注视转变的运动神经元。 为了 了解感觉运动整合的机制 中间灰色层，必须表征输入 负责前背束细胞的反应。 以前的 研究表明中间灰色层严重 由利用神经递质 γ- 的纤维支配 氨基丁酸（GABA）和乙酰胆碱。 拟议的实验 检查这两个光纤系统之间的关系 猫的背前束细胞。 实验检验假设 未定区是位于丘脑腹侧的一个核，是一个 这些细胞的 GABA 能输入的重要来源。 他们还测试 网状结构中的一群细胞的想法 脚桥被盖核，是胆碱能中继 基底神经节和前背束细胞的输出。 具体来说，这些实验设计为： 1. 定位、使用 逆行轴突运输方法，细胞的起源 incertotectal 途径并通过使用组合来确定 逆行追踪和免疫细胞化学方法，无论是否存在不确定带 是中间灰色层的 GABA 能输入源。 2. 到 表征超微结构特征和突触后目标 中间灰色层的 incertotectal 终止点 检查这些末端是否直接接触前背束 细胞，通过使用顺行和逆行追踪的组合 为电子显微镜制备的组织的方法。 3. 确定， 在组织中结合使用顺行和逆行方法 准备电镜观察，胆碱能细胞是否在 脚脚被盖核接收来自黑质的输入 网状部，基底神经节的传出核之一。 4. 至 表征胆碱能投射的突触后目标 从脚被盖核到中间灰质 层，并检查胆碱能末端是否接触 前背束细胞，通过使用顺行的组合， 在制备的组织中进行逆行和免疫细胞化学方法 电子显微镜。