Inspiratory-activated and inspiratory-inhibited airway vagal preganglionic neurons in the ventrolateral medulla of neonatal rat are different in intrinsic electrophysiological properties
Inspiratory-activated and inspiratory-inhibited airway vagal preganglionic neurons in the ventrolateral medulla of neonatal rat are different in intrinsic electrophysiological properties
复制标题
新生大鼠腹外侧延髓吸气激活和吸气抑制气道迷走神经节前神经元内在电生理特性不同
DOI：
10.1016/j.resp.2011.12.014
复制
发表时间：
2012-03-15
影响因子：
2.3
通讯作者：
Wang, Jijiang
中科院分区：
文献类型：
--
作者：
Chen, Yonghua;Hou, Lili;Wang, Jijiang
本研究探讨了位于模棱两可核外形成的气道迷走神经节前神经元的吸气激活和吸气抑制的放电特性。结果表明，吸气激活神经元和吸气抑制神经元在该区域具有不同的分布密度和位置偏好。在电流箝位下，吸气抑制的神经元表现出更高的静息膜电位，更高的负电压阈值和更低的动作电位所需的最小电流。吸入激活神经元的后超极化被钙离子激活的小电导K+通道的阻滞剂apamin阻断；而在吸入抑制的神经元中，碳毒素是一种大电导Ca2+激活的K+通道的阻滞剂。在电压箝位下，去极化电压阶跃诱发河豚毒素敏感的快速内向钠电流、4-氨基吡啶敏感的外向钾瞬态电流和持久外向钾电流。4-氨基吡啶部分阻断了吸气激活神经元的持久外向钾电流，但对吸气抑制神经元的持久外向钾电流无效。这些发现表明，吸气激活和吸气抑制神经元的组织结构不同，表达不同类型的电压门控离子通道。(C) 2011 Elsevier B.V.版权所有
This study investigates the firing properties of the inspiratory-activated and inspiratory-inhibited airway vagal preganglionic neurons located in the external formation of the nucleus ambiguus. The results showed that inspiratory-activated and inspiratory-inhibited neurons are distributed with different density and site preference in this area. Inspiratory-inhibited neurons exhibit significantly more positive resting membrane potential, more negative voltage threshold and lower minimal current required to evoke an action potential under current clamp. The afterhyperpolarization in inspiratory-activated neurons was blocked by apamin, a blocker of the small-conductance Ca2+-activated K+ channels; and that in inspiratory-inhibited neurons by charybdotoxin, a blocker of the large-conductance Ca2+-activated K+ channels. Under voltage clamp, depolarizing voltage steps evoked tetrodotoxin-sensitive rapid inward sodium currents, 4-aminopyridine-sensitive outward potassium transients and lasting outward potassium currents. 4-Aminopyridine partially blocked the lasting outward potassium currents of inspiratory-activated neurons but was ineffective on those of inspiratory-inhibited neurons. These findings suggest that inspiratory-activated and inspiratory-inhibited neurons are differentially organized and express different types of voltage-gated ion channels. (C) 2011 Elsevier B.V. All rights reserved.