Inhibitory effect of sympathetic stimulation on activities of masseter muscle spindles and the jaw jerk reflex in rats.
Inhibitory effect of sympathetic stimulation on activities of masseter muscle spindles and the jaw jerk reflex in rats.
复制标题
交感神经刺激对大鼠咬肌梭活动和下颌反射的抑制作用。
DOI：
10.1113/jphysiol.1995.sp020581
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发表时间：
1995
期刊：
影响因子：
--
通讯作者：
T. Morimoto
中科院分区：
文献类型：
--
作者：
R. Matsuo;A. Ikehara;T. Nokubi;T. Morimoto
1. 为了评价交感神经对下颚肌肉的影响，比较了麻醉后的大鼠在电刺激颈交感干前后咬肌纺锤体传入神经的放电、下颚肌肌电图（EMG）活动和血流变化。2. 为了排除三叉神经运动神经元输出控制的可能性，从咬肌神经的外周末端切下肌梭活动记录。用辣根过氧化物酶法证实咬肌神经中缺乏交感神经成分。3. 在生理频率范围内对交感神经进行电刺激，可减少被动张口引起的肌纺锤体传入放电。4. 交感神经刺激还能减少下巴抽搐反射引起的肌电图活动，这可能反映了交感神经对纺锤体传入神经的影响。在停止刺激后，观察到肌电图活动的短暂性增加，这可能是由于三叉神经运动神经元的传出供应。在有节奏的下颌运动中，没有检测到交感神经对肌电图活动的影响。5. 上述交感神经对肌纺锤体传入神经和肌电图活动的影响与血流变化无关。
1. To evaluate sympathetic effects on jaw muscles, the discharges of masseter muscle spindle afferents, jaw muscle electromyographic (EMG) activities and blood flow changes were compared in anaesthetized decerebrate rats before and during electrical stimulation of the cervical sympathetic trunk. 2. To eliminate the possibility of efferent control from the trigeminal motoneurones, muscle spindle activity was recorded from the cut peripheral end of the masseter nerve. The absence of a sympathetic component in the masseter nerve was confirmed by the horseradish peroxidase method. 3. Electrical stimulation of the sympathetic nerve at frequencies within the physiological range reduced muscle spindle afferent discharges evoked by passive jaw opening. 4. Sympathetic stimulation also reduced the EMG activity evoked by the jaw jerk reflex, which may reflect a sympathetic effect on spindle afferents. After cessation of stimulation, a transient increase in EMG activity was observed, which may be due to efferent supply from the trigeminal motoneurones. During rhythmical jaw movements, no sympathetic effect on EMG activity was detected. 5. The above sympathetic effect on muscle spindle afferents and EMG activity was independent of blood flow changes.