Excitatory and inhibitory postsynaptic potentials in cat hypoglossal motoneurons during swallowing
Excitatory and inhibitory postsynaptic potentials in cat hypoglossal motoneurons during swallowing
复制标题
猫吞咽过程中舌下运动神经元的兴奋性和抑制性突触后电位
作者：
N. Tomomune;M. Takata
摘要研究了猫吞咽过程中颏舌肌和茎舌肌运动神经元（GG-和SG-Mns）产生的突触后电位。在通过将水放在舌背上引发吞咽过程中，GG-肌肉放电80-210 ms（平均值±S.D. 123±31 ms，N=59）并突然受到抑制，SG-肌肉开始与GG-肌肉同步放电并放电200-360 ms（平均值±S. D. 247±36 ms，N=59）。 N=59）。如果单一肌肉活动一对一地跟随运动神经元的诱导尖峰，则可以识别 GG 和 SG-Mns。在吞咽过程中，无论 SG-Mns 上的呼吸驱动如何，在 SG-Mns 中都会诱发兴奋性突触后电位 (EPSP)，而无论 GG-Mns 上的呼吸驱动如何，都会在 GG-Mns 上诱发抑制性突触后电位 (IPSP) 或 EPSP-IPSP。通过增加细胞内氯离子浓度，吞咽过程中 GG-Mn 中引发的 IPSP 转化为去极化电位。在固定的猫中，通过对喉上神经的重复电刺激，在舌头牵缩运动神经元和舌头突出运动神经元上连续诱发去极化电位和去极化-超极化电位序列。
SummaryThe postsynaptic potentials produced in cat genioglossus and styloglossus motoneurons (GG- and SG-Mns) during swallowing were studied. During swallowing elicited by placing water on the dorsum of the tongue, the GG-muscle discharged for 80–210 ms (mean±S. D. 123±31 ms, N=59) and was abruptly suppressed, and the SG-muscle began discharging in synchrony with the GG-muscle and discharged for 200–360 ms (mean+ S. D. 247±36 ms, N=59). The GG and the SG-Mns were identified if unitary muscle activity followed the induced spike of the motoneuron one-for-one. During swallowing, excitatory postsynaptic potentials (EPSPs) were evoked in the SG-Mns regardless of the respiratory drive on the SG-Mns, and inhibitory postsynaptic potential (IPSP) or EPSP-IPSP was evoked on the GG-Mns regardless of the respiratory drive on the GG-Mns. By increasing the intracellular concentration of chloride ions, the IPSP elicited in the GG-Mn during swallowing was turned into a depolarizing potential. In immobilized cats, a depolarizing potential and a depolarizing-hyperpolarizing potential sequence was evoked successively on a tongue retractor motoneuron and a tongue protruder motoneuron by repetitive electrical stimulation of the superior laryngeal nerve.