Roda Fabrice, Pio Juliette, Bianchi Armand-Louis, Gestreau Christian
Laboratoire de Physiologie Neurovégétative, UMR Centre National de la Recherche Scientifique 6153, Institut National de la Recherche Agronomique 1147, Faculté des Sciences et Techniques Saint Jérôme, 13397 Marseille 20, France.
J Comp Neurol. 2004 Jan 19;468(4):571-86. doi: 10.1002/cne.10974.
This study examined the effects of anesthesia on the hypoglossal nerve and diaphragm activities and on c-Fos expression in brainstem hypoglossal premotor neurons (pmXII). Experiments were performed in 71 rats by using halothane inhalation, pentobarbital sodium, or mixtures of alpha-chloralose and urethane or ketamine and xylazine. First, various cardiorespiratory parameters were measured in the rats (n = 31) during both awake and anesthetized conditions. The volatile anesthetic halothane, but not the other anesthetics, was always associated with a strong phasic inspiratory activity in the hypoglossal nerve. Second, a double-immunohistochemical study was performed in awake and anesthetized rats (n = 40) to gauge the level of activity of pmXII neurons. Brainstem pmXII neurons were identified after microiontophoresis of the retrograde tracer Fluoro-Gold in the right hypoglossal motor nucleus. Patterns of c-Fos expression at different brainstem levels were compared in five groups of rats (i.e., awake or anesthetized with halothane, pentobarbital, chloralose-urethane, and ketamine-xylazine). Sections were processed for double detection of c-Fos protein and Fluoro-Gold by using the standard ABC method and a two-color peroxidase technique. Anesthesia with halothane induced the strongest c-Fos expression in a restricted pool of pmXII located in the pons at the level of the Kölliker-Fuse nucleus and the intertrigeminal region. The results demonstrated a major effect of halothane in inducing changes in hypoglossal activity and revealed a differential expression of c-Fos protein in pmXII neurons among groups of anesthetized rats. We suggest that halothane mediates changes in respiratory hypoglossal nerve discharge by altering activity of premotor neurons in the Kölliker-Fuse and intertrigeminal region.
本研究考察了麻醉对舌下神经和膈肌活动以及对脑干舌下运动前神经元（pmXII）中c-Fos表达的影响。实验采用71只大鼠，通过吸入氟烷、戊巴比妥钠，或使用α-氯醛糖与乌拉坦或氯胺酮与赛拉嗪的混合物进行。首先，在清醒和麻醉状态下测量了31只大鼠的各种心肺参数。挥发性麻醉剂氟烷，而非其他麻醉剂，总是与舌下神经强烈的相位性吸气活动相关。其次，对40只清醒和麻醉大鼠进行了双重免疫组织化学研究，以评估pmXII神经元的活动水平。在右侧舌下运动核微量离子导入逆行示踪剂荧光金后，识别出脑干pmXII神经元。比较了五组大鼠（即清醒、氟烷麻醉、戊巴比妥麻醉、氯醛糖-乌拉坦麻醉和氯胺酮-赛拉嗪麻醉）在不同脑干水平的c-Fos表达模式。切片采用标准ABC法和双色过氧化物酶技术进行处理，以双重检测c-Fos蛋白和荧光金。氟烷麻醉在位于脑桥Kölliker-Fuse核和三叉神经间区域水平的有限pmXII池中诱导了最强的c-Fos表达。结果表明氟烷在诱导舌下活动变化方面有主要作用，并揭示了麻醉大鼠组中pmXII神经元c-Fos蛋白的差异表达。我们认为氟烷通过改变Kölliker-Fuse核和三叉神经间区域运动前神经元的活动来介导呼吸性舌下神经放电的变化。
