Gold B G, Griffin J W, Price D L, Cork L C, Lowndes H E
Brain Res. 1986 Jan 8;362(2):205-13. doi: 10.1016/0006-8993(86)90445-2.
beta, beta'-Iminodipropionitrile (IDPN) produces neurofilamentous giant axonal swellings in proximal internodes of large myelinated axons. Secondary demyelinative changes result from the production of these axonal enlargements. Electrophysiological studies have demonstrated profound alterations in the electrical properties of motor neurons (MN) within the spinal cord. On the basis of intracellular recordings, it has been suggested that electrical contacts may exist between swollen axons and neighboring MN. In addition, the possibility remained that synaptic contacts develop on demyelinated axonal swellings. In the present study, we report the lack of either synapses on demyelinated axonal swellings or direct electrical contacts between neighboring MN. Axonal swellings are surrounded by attenuated processes of glial cells (probably fibrillary astrocytes), a finding discussed in terms of its possible role in the production of ephaptic transmission. There was considerable variation in the degree of axonal enlargements and in the extent of secondary (passive and active) demyelination. It is suggested that these morphological changes may represent structural correlates of some electrophysiological alterations observed in IDPN neuropathy.
β,β'-亚氨基二丙腈（IDPN）在大型有髓轴突的近端节间产生神经丝性巨大轴突肿胀。这些轴突增大导致继发性脱髓鞘改变。电生理研究表明脊髓内运动神经元（MN）的电特性发生了深刻变化。根据细胞内记录，有人提出肿胀的轴突与相邻的MN之间可能存在电接触。此外，脱髓鞘的轴突肿胀上形成突触接触的可能性仍然存在。在本研究中，我们报告在脱髓鞘的轴突肿胀上既没有突触，相邻的MN之间也没有直接的电接触。轴突肿胀被神经胶质细胞（可能是纤维性星形胶质细胞）的变细突起所包围，这一发现从其在产生ephaptic传递中可能发挥的作用方面进行了讨论。轴突增大的程度和继发性（被动和主动）脱髓鞘的范围存在相当大的差异。有人提出，这些形态学变化可能代表了在IDPN神经病中观察到的一些电生理改变的结构相关因素。
