Csillik B
Department of Anatomy, University Medical School, Szeged, Hungary.
Acta Physiol Hung. 1987;69(3-4):355-61.
Central terminals of the primary sensory neurons depend on the integrity of the retrograde transport mechanism within the peripheral axon. Whenever retrograde transport is impaired (either by injury or by blockade induced by perineural application of microtubule inhibitors) central terminals undergo transganglionic degenerative atrophy (TDA), characterized by depletion of substance P, somatostatin, FRAP (fluoride resistant acid phosphatase), TMPase (thiamine monophosphatase) and lectin-binding fucose-terminated glyco-conjugates. The TDA is essentially a failure of the central terminals to bind the above genuine marker substances. TDA-inflicted central terminals undergo a slowly proceeding ultrastructural deterioration, accompanied by derangement of the dorsal root potential, reflecting decreased functional activity of synaptic transmission between first and second-order cells. One of the important trophic substances carried by retrograde axoplasmic transport to dorsal root ganglion cells is nerve growth factor (NGF); blockade of NGF transport results in TDA; conversely, locally applied NGF delays or prevents TDA.
初级感觉神经元的中枢终末依赖于外周轴突内逆行运输机制的完整性。每当逆行运输受损（无论是因损伤还是因经神经周围应用微管抑制剂诱导的阻断）时，中枢终末就会发生跨神经节变性萎缩（TDA），其特征是P物质、生长抑素、FRAP（耐氟酸性磷酸酶）、TMPase（硫胺素单磷酸酶）和凝集素结合的岩藻糖末端糖缀合物耗竭。TDA本质上是中枢终末无法结合上述真正的标记物质。受TDA影响的中枢终末会经历缓慢进展的超微结构恶化，同时伴有背根电位紊乱，这反映了一级和二级细胞之间突触传递功能活性的降低。通过逆行轴浆运输输送到背根神经节细胞的重要营养物质之一是神经生长因子（NGF）；阻断NGF运输会导致TDA；相反，局部应用NGF可延迟或预防TDA。
