BRAINSTEM PATHWAYS CONTROLLING EYE MOVEMENT

有大量证据表明，中脑导水管周围的神经元 灰质区(PAG)在中枢痛觉调制中的重要作用 并部分介导全身吗啡的镇痛作用。 从PAG到延髓中缝区的下行联系(尤其是 中缝大核)和PAG向丘脑的上行投射 (包括腹基复合体)可能是基础的重要通路 这些影响。更好地定义解剖组织和功能 在此基础上，我们将进行一系列的实验来研究PAG的性能。 传出联系、递质组织化学和电生理学 PAG细胞。具体项目将：一.确定个别PAG是否 神经元投射到腹基底核复合体和中缝大核。这个 投射到腹基底核复合体和中缝的PAG神经元的分布 马格努斯将用双标记逆行运输方法进行研究 辣根过氧化物酶和荧光素。双重标签技术将 确定是否有下行连接的相同PAG神经元 大缝中缝也直接投射到丘脑。二、找出 投射到腹基底核复合体的OAG神经元的神经肽含量 或者是拉菲·马格努斯。大量研究提供了证据表明，特定的 神经肽可能在PAG介导的体感效应中起重要作用。 将采用逆行运输-免疫细胞化学相结合的方法 确定哪些神经肽与投射的PAG神经元有关 腹底复合体或大中缝复合体。描述传入者的特征 对PAG神经元的输入。异地识别的PAG神经元投射到 将使用细胞内技术研究丘脑或中缝大核 麻醉、瘫痪猫的电生理学方法。这个 这类细胞对杏仁核电击刺激的顺行反应， 下丘脑外侧、延髓网状结构和内囊 将会被确定。孤束核神经元对潜在伤害性物质的反应 周围神经和牙髓的休克刺激也将 调查过了。四、电生理解剖学研究 以PAG神经元为特征。选定的、电生理定义的PAG 细胞内的神经元将被辣根过氧化物酶染色。这个 三叉神经节的定位、躯体树突分支和初始轴突投射 这些细胞将在光学显微镜水平上使用 相机光感技术。细胞内染色将使我们有可能 确定电生理上不同的PAG神经元是否也 在它们的位置、外观和传出的突起上截然不同。

There is substantial evidence that neurons in the midbrain periaqueductal grey region (PAG) play an important role in the modulation of central pain pathways and partially mediate the analgesic effects of systemic morphine. Descending connections from PAG to the medullary raphe region (particularly nucleus raphe magnus) and ascending projections from PAG to the thalamus (including the ventrobasal complex) may be important pathways that underlie these effects. To define better the anatomic organization and functional circuitry of PAG, a series of experiments will be performed to study the efferent connections, transmitter histochemistry, and electrophysiology of PAG cells. Specific projects will: I. Determine whether individual PAG neurons project to both the ventrobasal complex and raphe magnus. The distribution of PAG neurons projecting to the ventrobasal complex and raphe magnus will be studied with double-label retrograde transport methods using horseradish peroxidase and fluorochromes. Double-label techniques will determine whether the same PAG neurons that have descending connections to raphe magnus also project directly to the thalamus. II. Identify the neuropeptide content of OAG neurons that project to the ventrobasal complex or raphe magnus. Numerous studies provide evidence that specific neuropeptides may be important in PAG-mediated somatosensory effects. Combined retrograde transport-immunocytochemical methods will be used to determine which neuropeptides are associated with PAG neurons that project to the ventrobasal complex or raphe magnus. III. Characterize the afferent inputs to PAG neurons. Antidomically identified PAG neurons projecting to thalamus or raphe magnus will be studied using intracellular electrophysiologic methods in anesthetized, paralyzed cats. The orthodromic responses of such cells to shock stimulation of the amygdala, lateral hypothalamus, medullary reticular formation and internal capsule will be determined. The response of PAG neurons to potentially noxious shock stimulation of peripheral nerves and tooth pulp will also be investigated. IV. Study the anatomy of electrophysiologically characterized PAG neurons. Selected, electrophysiologically defined PAG neurons will be intracellularly stained with horseradish peroxidase. The location, somatodendritic arboriztion, and initial axonal projection of these cells will be reconstructed at the light microscope level using camera lucida techniques. Intracellular staining will make it possible to determine whether PAG neurons that differ electrophysiologically are also distinct in their location, appearance, and efferent projections.