Structural basis of sympathetic-sensory coupling in rat and human dorsal root ganglia following peripheral nerve injury
Structural basis of sympathetic-sensory coupling in rat and human dorsal root ganglia following peripheral nerve injury
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DOI：
10.1023/a:1007090105840
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发表时间：
1999-09-01
期刊：
影响因子：
--
通讯作者：
Devor, M
中科院分区：
文献类型：
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作者：
Shinder, V;Govrin-Lippmann, R;Devor, M
应用酪氨酸羟化酶免疫细胞化学方法，观察了坐骨神经损伤后背根神经节内部分初级感觉神经元胞体周围的交感神经节后轴突萌发，形成篮状丝蛋白。对大鼠的超微结构观察显示，这些芽生长在神经元上形成的神经胶质层表面。坐骨神经损伤引起DRG内胶质细胞的增殖，并形成多层细胞周围的洋葱球鞘，主要围绕大直径的DRG神经元。我们推测，这些胶质细胞通过释放神经营养因子和表达支持生长的细胞表面分子来参与发芽过程。许多DRG细胞胞体及其在完整神经和神经末梢神经瘤中的轴突在胞浆内和膜表面表达α2A型肾上腺素受体。然而，交感神经轴突从不与胞体膜直接接触。因此，交感传出神经元和背根节神经元之间发生的功能性耦合必须通过神经递质分子在细胞外空间的扩散来调节。在从人类神经病理性疼痛患者中移除的DRG中观察到交感神经篮-丝蛋白，但这些结构与感觉症状之间功能联系的可能性仍然是推测的。
Tyrosine hydroxylase immunocytochemistry was used to reveal the sympathetic postganglionic axons that sprout to form basket-like skeins around the somata of some primary sensory neurons in dorsal root ganglia (DRGs) following sciatic nerve injury. Ultrastructural observations in rats revealed that these sprouts grow on the surface of glial lamellae that form on the neurons. Sciatic nerve injury triggers glial cell proliferation in the DRG, and the formation of multilamellar pericellular onion bulb sheaths, primarily around large diameter DRG neurons. We infer that these glia participate in the sprouting process by releasing neurotrophins and expressing growth supportive cell surface molecules. Many DRG cell somata, and their axons in intact nerves and nerve end neuromas, express alpha 2A adrenoreceptors intracytoplasmically and on their membrane surface. However, sympathetic axons never make direct contacts with the soma membrane. The functional coupling known to occur between sympathetic efferents and DRG neurons must therefore be mediated by the diffusion of neurotransmitter molecules in the extracellular space. Sympathetic basket-skeins were observed in DRGs removed from human neuropathic pain patients, but the possibility of a functional relation between these structures and sensory symptoms remains speculative.