NEUROTRANSMITTERS IN DRGS & SOMESTHESIC PATHS.

拟议的研究涉及以下几个方面： 脊髓和背侧的神经传递/神经调节 大鼠和猫的柱核。 三个主要目标之一是 确定谷氨酸免疫反应性是否与 P物质或其他肽的免疫反应性 初级传入纤维终末至皮层浅层 脊髓背角 为此，免疫细胞化学 将采用电子显微镜的双标记方法。 还将进行实验以确定以下物质的共存 背根神经节神经元胞体中谷氨酸与肽的关系。 光学显微镜双标记方法的类型已经 在这个实验室里用来证明谷氨酸盐 和P物质将用于拟议的 research. 第二个系列的实验旨在确定是否在 至少有一些脊髓神经元在起源的非初级 （突触后）传入到背柱核和在 大鼠脊髓-丘脑束的起源含有P物质。 这部分拟议研究的主要战略包括 双标记脊髓神经元的逆行转运 二脒基黄注射到背柱核或神经元。 丘脑腹后外侧肌免疫细胞化学染色 逆行双标记实验将是 辅以顺行双标记观察 技术和物质突触关系研究 P-阳性终末见于背柱核和核团。 丘脑后外侧腹侧肌 第三个目标是研究抑制性的意义。 猫背柱核的GABA能机制。 的 实验包括研究电生理反应， 丘脑投射神经元在楔状核的各种 电离子透入时周围刺激的类型 已知阻断GABAA受体的甲溴荷包牡丹碱。 与 这些实验预计将收集有关信息 抑制在调节感觉输入中的作用， 内侧丘系系统第一层的神经元。

The proposed research deals with several aspects of neurotransmission/neuromodulation in the spinal cord and dorsal column nuclei of rats and cats. One of the three main goals is to establish whether glutamate immunoreactivity co-exists with immunoreactivity for substance P or other peptides in the same terminal of primary afferent fibers to the superficial laminae of the spinal dorsal horn. For this purpose, immunocytochemical double-labeling methods for electron microscopy will be employed. Experiments will be also performed to establish co-existence of glutamate with peptides in neuronal somata of dorsal root ganglia. Light microscopical double-labeling methods of the type already employed in this laboratory to demonstrate coexistence of glutamate and substance P will be used for this part of the proposed research. A second series of experiments is designed to establish whether at least some of the spinal neurons at the origin of non-primary (postsynaptic) afferents to the dorsal column nuclei and at the origin of the spino-thalamic tract in rats contain substance P. The main strategy for this part of the proposed research consists of double-labeling spinal neurons by retrograde transport of Diamidino Yellow injected in either dorsal column nuclei or n. ventralis posterolateralis of thalamus by immunocytochemistry for substance P. The retrograde double-labeling experiments will be supplemented by observations with an anterograde double-labeling technique and by an investigation of synaptic relation of substance P-positive terminals in both the dorsal column nuclei and the n. ventralis posterolateralis of thalamus. A third goal is to investigate the significance of inhibitory GABAergic mechanisms in the dorsal column nuclei of cats. The experiments consist of studying the electrophysiological responses of thalamic projecting neurons in the cuneate nucleus to various types of peripheral stimuli during iontophoretic ejection of bicuculline methobromide, known to block GABAA receptors. With these experiments it is expected to gather information concerning the role of inhibition in the modulation of sensory input to neurons at the first level of the medial lemniscal system.