Blockade of inhibitory neurotransmission evoked seizure-like activation of preganglionic cardiac parasympathetic neurons in nucleus ambiguus of newborn rats

【作者】 王继江； 陈咏华； 李克勇； 孙凤艳；

【机构】 复旦大学上海医学院；

【摘要】 <正>A proportion of unexplained sudden death in patients of epilepsy had been attributed to neurogenic arrhythmia. Recent evidence showed that anomalous activation of cardiac parasympathetic nerve during epileptic attack, which is revealed by ictal bradyarrhythmia or cardiac asystole, might be very critical in causing sudden death. In this study preganglionic cardiac parasympathetic neurons (CPNs), which were antidromically labeled and identified by presence of fluorescence in brainstem slices of newborn rats, were examined with whole-cell patch-clamp methods under seizure-evoking condition. We have demonstrated that in isolated brainstem slices of newborn rats blockade of GABAergic and glycinergic receptors evoked intermittent seizure-like activation of CPNs, which was synchronous with the seizure-like discharge of hypoglossal nerve. The intermittent seizure-like activation of CPNs was primarily mediated by presynaptic release of glutamatergic neurotransmitters, which activated both NMDA and non-NMDA glutamatergic receptors in CPNs, and might also involve activation of nicotinic cholinergic receptors and gap junctions in CPNs. This study suggested that the neurogenic ictal bradyarrhythmia during epileptic attack might be mediated by seizure-like discharge of CPNs.更多还原