Gerstner G E, Goldberg L J
Department of Oral Biology, School of Dentistry, University of California, Los Angeles 90024-166818.
Brain Res. 1991 Oct 18;562(1):79-84. doi: 10.1016/0006-8993(91)91189-8.
The electromyograph (EMG) activity of the left anterior digastric and the genioglossus muscles was studied in ketamine-anesthetized guinea pigs under 3 separate jaw movement paradigms. The first paradigm has been previously named spontaneous rhythmic jaw movements. These jaw movements occur 1-2 h after the onset of ketamine anesthesia. After spontaneous rhythmic jaw movements began, a single dose of apomorphine caused a new, second jaw movement paradigm to occur, apomorphine-induced rhythmic jaw movements. The final paradigm, cortically-evoked rhythmic jaw movements, was elicited by electrical stimulation of the masticatory area of the cerebral cortex. Genioglossus EMG activity was complex and highly variable in spontaneous rhythmic jaw movements; however, apomorphine-induced jaw movements were characterized by simultaneously occurring rhythmic EMG bursts of approximately 230 ms duration in both the digastric and genioglossus muscles. In 4 of 5 animals, genioglossus muscle activity onset preceded digastric muscle activity onset by approximately 20 ms. These results support the hypothesis that apomorphine-induced rhythmic jaw movements are an analog of lapping in the awake animal. In cortically-evoked rhythmic jaw movements, both digastric and genioglossus EMG activity were time-locked to the cortical electrical stimulation, with an onset latency of approximately 11 ms for the digastric EMG activity and of 16 ms for the genioglossus EMG activity. These results support the hypothesis that both trigeminal and hypoglossal motoneuron pools are closely coupled in certain coordinative movement patterns.
在氯胺酮麻醉的豚鼠身上，在三种不同的下颌运动范式下研究了左前腹直肌和颏舌肌的肌电图（EMG）活动。第一种范式先前被命名为自发性节律性下颌运动。这些下颌运动在氯胺酮麻醉开始后1 - 2小时出现。在自发性节律性下颌运动开始后，单剂量的阿扑吗啡导致了一种新的、第二种下颌运动范式的出现，即阿扑吗啡诱导的节律性下颌运动。最后一种范式，即皮层诱发的节律性下颌运动，是通过电刺激大脑皮层的咀嚼区域引发的。在自发性节律性下颌运动中，颏舌肌的EMG活动复杂且高度可变；然而，阿扑吗啡诱导的下颌运动的特征是，在腹直肌和颏舌肌中同时出现持续约230毫秒的节律性EMG爆发。在5只动物中的4只中，颏舌肌活动开始比腹直肌活动开始早约20毫秒。这些结果支持了这样一种假设，即阿扑吗啡诱导的节律性下颌运动类似于清醒动物的舐食动作。在皮层诱发的节律性下颌运动中，腹直肌和颏舌肌的EMG活动都与皮层电刺激时间锁定，腹直肌EMG活动的起始潜伏期约为11毫秒，颏舌肌EMG活动的起始潜伏期约为16毫秒。这些结果支持了这样一种假设，即在某些协调运动模式中，三叉神经和舌下运动神经元池紧密耦合。
