Carr P A, Yamamoto T, Karmy G, Nagy J I
Department of Physiology, Faculty of Medicine, University of Manitoba, Winnipeg, Canada.
Brain Res Bull. 1991 Jun;26(6):825-43. doi: 10.1016/0361-9230(91)90246-g.
Light and electron microscopic immunohistochemical techniques were used to investigate the central projections and colocalization relationships of a subpopulation of primary afferent neurons that were immunolabelled with an antibody (AB893) against rat liver gap junctions. In lumbar dorsal root ganglia AB893-immunoreactivity was seen in 14.5% of all cells and in both small and large size neurons. Colocalization analysis showed that 78% of all AB893-immunoreactive (AB893-IR) neurons contained calcitonin gene-related peptide, while only 7 to 10% contained the calcium binding proteins parvalbumin or calbindin D28k. Among small type B AB893-IR ganglion cells, it was calculated that over 90% contained fluoride-resistant acid phosphatase, while only 1 to 2% contained substance P or somatostatin. Cytochrome oxidase histochemistry revealed light staining in the vast majority of AB893-IR cells. In the dorsal horn of the spinal cord the antibody labelled fibers in the dorsal root, Lissauer's tract, lamina I and lamina II. Isolated immunoreactive fiber bundles were arranged in sheets spanning most of lamina II. Immunoreactive fibers were depleted from the dorsal horn after dorsal rhizotomy or neonatal capsaicin treatment. Ultrastructural examination showed that AB893-IR fibers were composed of closely associated clusters of 2 to 5 unmyelinated fibers each ranging from 0.1-0.4 microns in diameter. Immunoreactivity was distributed intermittently along the cytoplasmic membrane of axons and en passant sinusoid terminals located centrally within the fiber clusters, as well as along axonal membranes adjacent to the central axon or terminal. The results suggest that the immunoreactive fibers in lamina II of the dorsal horn originate from a subpopulation of AB893-IR neurons that contain FRAP and give rise to unmyelinated axons.
采用光镜和电镜免疫组织化学技术，研究了一群初级传入神经元的中枢投射及共定位关系，这群神经元用抗大鼠肝间隙连接的抗体（AB893）进行免疫标记。在腰段背根神经节中，14.5%的所有细胞以及大小神经元中均可见AB893免疫反应性。共定位分析表明，所有AB893免疫反应性（AB893-IR）神经元中，78%含有降钙素基因相关肽，而仅7%至10%含有钙结合蛋白小白蛋白或钙结合蛋白D28k。在小型B型AB893-IR神经节细胞中，经计算超过90%含有耐氟酸性磷酸酶，而仅1%至2%含有P物质或生长抑素。细胞色素氧化酶组织化学显示，绝大多数AB893-IR细胞呈淡染色。在脊髓背角，该抗体标记了背根、Lissauer束、I层和II层中的纤维。孤立的免疫反应性纤维束呈片状排列，跨越大部分II层。背根切断术或新生鼠辣椒素处理后，背角中的免疫反应性纤维减少。超微结构检查显示，AB893-IR纤维由紧密相连的2至5个无髓纤维簇组成，每个纤维直径为0.1-0.4微米。免疫反应性沿轴突的细胞质膜间断分布，以及位于纤维簇中央的过路窦状终末分布，也沿与中央轴突或终末相邻的轴突膜分布。结果表明，背角II层中的免疫反应性纤维起源于一群含有FRAP并产生无髓轴突的AB893-IR神经元。
