SENSORY PROCESSING AND ITS RELATION TO ORAL-FACIAL PAIN

中枢神经系统中的感觉处理涉及到 和下行通道。例如，上升的伤害性冲动 中度口腔-面部疼痛，受下行控制系统的影响 主要起源于脑干。在视觉系统中，上升 来自视网膜的脉冲受到下行控制系统的影响 起源于大脑皮层。这项拟议的研究考察了两个 下行调节通路和上行感觉通路。 第一阶段下行至上丘的纤维来自广泛的 纹前皮质、颞叶皮质和顶叶皮质。电生理学 对猴子的行为研究表明，这种皮质顶盖系统 在视觉运动整合中起着重要的调节作用。个体 这个系统的组件是从每一个已知的 视觉皮质。皮质顶盖细胞的每个成分都可能形成唯一的 视觉区域内的细胞亚群，它们来自 起源。我们在第一阶段的目标是检查这样一个组件，即， 纹外区的皮质顶盖通路。视觉反应 MT中单个皮质顶盖细胞的特性将用 麻醉猴子的微电极记录，并与 控制未投射到丘脑的MT细胞的数量。 第二阶段：口腔上行伤害性信息是 由浅层长投射神经元传递到丘脑 延髓背角的第V层和第V层。我们在第二阶段的目标是 确定无髓鞘初级传入是否存在突触 三叉神经板的三叉神经丘脑细胞--已鉴定 通过对侧丘脑的逆行激活，将被填充 辣根过氧化物酶(HRP)和无髓原代细胞的终末 传入纤维将用注射的正交线传输的HRP标记 进入背根神经节。填充单元格的形态特征 以及这些细胞之间的突触相互作用 将分析已标记的端子。

Sensory processing in the central nervous system involves both ascending and descending pathways. For example, ascending nociceptive impulses which mediate oral-facial pain, are influenced by descending control systems originating mainly in the brain stem. In the visual system, ascending impulses from the retina are influenced by descending control systems originating in the cortex. The proposed research examines both a descending modulatory pathway and an ascending sensory pathway. Phase I. Fibers descending to the superior colliculus arise from a wide expanse of prestriate, temporal and parietal cortex. Electrophysiological and behavioral studies in monkeys indicate that this corticotectal system plays an important modulatory role in visuomotor integration. Individual components of this system descend from each of the known subdivisions of visual cortex. Corticotectal cells of each component may form a unique subpopulation of cells within the visuotopic area from which they originate. Our goal in Phase I is to examine one such component namely, the corticotectal pathway from extrastriate area MT. The visual response properties of individual corticotectal cells in MT will be examined with microelectrode recordings in the anesthetized monkey, and compared to a control population of MT cells which do not project to the colliculus. Phase II. Ascending nociceptive information from the oral cavity is relayed to the thalamus by long projection neurons in the superficial layers and lamina V of the medullary dorsal horn. Our goal in Phase II is to determine whether unmyelinated primary afferents synapse on trigeminothalamic cells of lamina V. Trigeminothalamic neurons, identified by antidromic activation from the contralateral thalamus, will be filled with horseradish peroxidase (HRP), and terminals of unmyelinated primary afferent fibers will be labeled with orthogradely transported HRP injected into the dorsal root ganglion. The morphological features of filled cells will be described and the synaptic interaction between these cells and labeled terminals will be analyzed.