Vagotomy decreases excitability in primary vagal afferent somata
Vagotomy decreases excitability in primary vagal afferent somata
复制标题
DOI：
10.1152/jn.2001.85.1.247
复制
发表时间：
2001-01-01
影响因子：
2.5
通讯作者：
Weinreich, D
中科院分区：
文献类型：
--
作者：
Lancaster, E;Oh, EJ;Weinreich, D
使用标准膜片钳和细胞内记录技术监测迷走神经节切断（迷走神经切断术）后5天成人迷走神经下节神经元（结状神经节神经元，NGN）的膜兴奋性变化。NGN在迷走神经切断术后在体内维持5天，然后在记录之前在体外维持2-9小时。迷走神经切断术使动作电位（AP）阈值增加了200%以上（264 +/- 19 pA，平均值+/- SE，= 66），而对照组为81 +/- 20 pA，n = 68; P < 0.001）。3倍阈值750 ms去极化电流诱发的AP数目减少70%以上（从8.3到2.3个AP，P < 0.001）和由标准化系列刺激诱发的AP数量。（0.1-0.9 nA，750 ms）在迷走神经切断的NGN中，去极化电流阶跃减少了80%以上（从16.9个AP减少到2.6个AP，P < 0.001）。使用“尖锐”微电极技术进行的体外研究中，在完整神经节中切断迷走神经的NGN中观察到了类似的兴奋性下降。基线电生理特性和迷走神经切断术后的变化在右侧和左侧NGN中相似。一个“假”迷走神经切断术程序在5天对NGN的性能没有影响，表明变化是由于切断迷走神经本身，而不是周围组织损伤。迷走神经切断术后在体内维持17小时后分离的NGN显示兴奋性没有差异，表明迷走神经切断术诱导的变化发生在损伤后1-5天的某个时间。在迷走神经切断术后20-21天在体内分离的NGN中仍然观察到兴奋性降低。这些数据表明，与许多初级感觉神经元（被认为在切断其轴突后变得过度兴奋）相反，NGN在迷走神经切断术后电兴奋性显著降低。
Standard patch-clamp and intracellular recording techniques were used to monitor membrane excitability changes in adult inferior vagal ganglion neurons (nodose ganglion neurons, NGNs) 5 days following section of the vagus nerve (vagotomy). NGNs were maintained in vivo for 5 days following vagotomy, and then in vitro for 2-9 h prior to recording. Vagotomy increased action potential (AP) threshold by over 200% (264 +/- 19 pA, mean +/- SE, = 66) compared with control values (81 +/- 20 pA, n = 68; P < 0.001). The number of APs evoked by a 3 times threshold 750-ms depolarizing current decreased by >70% (from 8.3 to 2.3 APs, P < 0.001) and the number of APs evoked by a standardized series of (0.1-0.9 nA, 750 ms) depolarizing current steps decreased by over 80% (from 16.9 APs to 2.6 APs, P < 0.001) in vagotomized NGNs. Similar decreases in excitability were observed in vagotomized NGNs in intact ganglia in vitro studied with "sharp" microelectrode techniques. Baseline electrophysiological properties and changes following vagotomy were similar in right and left NGNs. A "sham" vagotomy procedure had no effect on NGN properties at 5 days, indicating that changes were due to severing the vagus nerve itself, not surrounding tissue damage. NGNs isolated after being maintained 17 h in vivo following vagotomy revealed no differences in excitability, suggesting that vagotomy-induced changes occur some time from 1-5 days after injury. Decreased excitability was still observed in NGNs isolated after 20-21 days in vivo following vagotomy. These data indicate that, in contrast to many primary sensory neurons that are thought to become hyperexcitable following section of their axons, NGNs undergo a marked decrease in electrical excitability following vagotomy.