Asada Y, Bennett M V
J Cell Biol. 1971 Apr;49(1):159-72. doi: 10.1083/jcb.49.1.159.
Adjacent segments of the septate axon of the crayfish Procambarus are electrotonically coupled by junction located in the septa between them (see Pappas et al. 1970. J. Cell Biol.49:173). The coupling resistance at the septa was changed by several experimental treatments. Mechanical injury to an axon increased coupling resistance (more than 7-fold); no recovery of coupling resistance was observed, although the resting potential and resistance of the injured axon could return to near normal levels. Immersion in salines with Na propionate substituted for NaCl increased coupling resistance (mean: 6.1-fold). On return of the preparation to normal saline, coupling resistance recovered virtually completely. Immersion in low Ca(++) solutions moderately increased coupling resistance (3.5-fold or less), but return to normal saline was followed by large increases in coupling resistance (5-100-fold). 60 nM Ca(++) is near the maximum concentration that leads to increased coupling resistance on return to normal saline. Large increases in coupling resistance are associated with separation of junctional membranes (Pappas et al. 1970. Ibid.); calculations show that the separated membranes greatly increase in resistance. Increase in coupling resistance is probably an important response to injury. Mechanisms underlying changes reported here may be relevant to normal physiological processes of coupling and decoupling.
小龙虾原螯虾的分隔轴突的相邻节段通过位于它们之间隔膜处的连接进行电紧张偶联（见帕帕斯等人，1970年。《细胞生物学杂志》49:173）。通过几种实验处理改变了隔膜处的偶联电阻。对轴突的机械损伤增加了偶联电阻（超过7倍）；尽管受损轴突的静息电位和电阻可恢复到接近正常水平，但未观察到偶联电阻的恢复。浸入用丙酸钠替代氯化钠的盐溶液中会增加偶联电阻（平均：6.1倍）。当制剂回到正常盐溶液中时，偶联电阻几乎完全恢复。浸入低钙（++）溶液中适度增加了偶联电阻（3.5倍或更小），但回到正常盐溶液后偶联电阻大幅增加（5 - 100倍）。60 nM钙（++）接近回到正常盐溶液时导致偶联电阻增加的最大浓度。偶联电阻的大幅增加与连接膜的分离有关（帕帕斯等人，1970年。同前）；计算表明分离的膜电阻大幅增加。偶联电阻的增加可能是对损伤的一种重要反应。此处报道的变化背后的机制可能与偶联和解偶联的正常生理过程相关。
