Kogo N, Remmers J E
Department of Medical Physiology, Faculty of Medicine, University of Calgary, Canada.
J Neurobiol. 1994 Sep;25(9):1080-94. doi: 10.1002/neu.480250905.
The paralyzed, decerebrate frog, Rana catesbeiana, displays "fictive" oropharyngeal and pulmonary ventilations. In order to evaluate the neuronal correlates of these two centrally programmed ventilatory bursting patterns, we have performed intra- and extracellular recordings of bulbar respiratory neurons in this fictively breathing preparation. A total of 123 respiratory neurons were recorded from the caudal medulla. Of 51 antidromically activated neurons, 20 were vagal motoneurons and 31 were hypoglossal motoneurons. Respiratory neurons that depolarized during the lung (L) or non-lung (N) ventilatory phases were classified as L or N neurons, respectively. Phase spanning neurons (S) were active during both L and N phases. Some neurons showed oscillations of membrane potential synchronous with oropharyngeal ventilation. Those active during the buccal elevation phase were exclusively L neurons, whereas those having buccal depressor activity were exclusively N neurons. Synaptic drive potentials were observed in all neurons recorded intracellularly. In some neurons, hyperpolarization was caused by inhibitory postsynaptic potentials, as demonstrated by reversal of membrane potential trajectory after intracellular chloride iontophoresis. Some individual motoneurons and interneurons exhibited both pulmonary and buccal ventilatory activity, indicating that both pattern generators project to a common motor control system.
瘫痪的牛蛙（Rana catesbeiana）呈现出“虚构的”口咽和肺部通气。为了评估这两种中枢编程的通气爆发模式的神经元相关性，我们在这种虚构呼吸准备中对延髓呼吸神经元进行了细胞内和细胞外记录。从延髓尾部总共记录了123个呼吸神经元。在51个逆向激活的神经元中，20个是迷走运动神经元，31个是舌下运动神经元。在肺部（L）或非肺部（N）通气阶段去极化的呼吸神经元分别被归类为L或N神经元。跨阶段神经元（S）在L和N阶段均活跃。一些神经元表现出与口咽通气同步的膜电位振荡。在颊部抬高阶段活跃的那些神经元仅为L神经元，而具有颊部下压活动的那些神经元仅为N神经元。在所有细胞内记录的神经元中都观察到了突触驱动电位。在一些神经元中，超极化是由抑制性突触后电位引起的，细胞内氯离子电泳后膜电位轨迹的反转证明了这一点。一些单个的运动神经元和中间神经元表现出肺部和颊部通气活动，表明这两种模式发生器都投射到一个共同的运动控制系统。
