Coordination of intrinsic and extrinsic tongue muscles during spontaneous breathing in the rat
Coordination of intrinsic and extrinsic tongue muscles during spontaneous breathing in the rat
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DOI：
10.1152/japplphysiol.00733.2003
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发表时间：
2004-02-01
影响因子：
3.3
通讯作者：
Fregosi, RF
中科院分区：
文献类型：
--
作者：
Bailey, EF;Fregosi, RF
舌功能的肌肉-静水模型提出了在所有舌运动中外在（外部骨附着，插入舌根）和内在（起源和插入舌内）舌肌肉的恒定相互作用（Kier WM和Smith KK. Zool J Linn Soc 83：207 - 324，1985）。然而，研究哺乳动物舌头功能的相关影响的研究仍然几乎完全集中在呼吸控制和外部舌前肌，颏舌肌的功能。舌内肌的呼吸控制和功能尚不清楚。我们的目的是确定内在舌肌是否有呼吸相关的活动模式，以及内在舌肌是否与外在舌肌共同激活，以响应呼吸相关的感官刺激。在麻醉、气管切开、自主呼吸的大鼠中，研究了食管压力和舌外肌（舌骨舌肌）、舌内肌（上级纵肌）和肋间外肌的肌电图（EMG）活动。平均吸气肌电图活动进行了比较，在五个水平的吸入二氧化碳。内源性舌肌在正常呼吸时常处于静止状态，但在高碳酸血症时活跃，而外源性舌肌在正常呼吸和高碳酸血症时均活跃。在高碳酸血症期间，气道肌肉的活动在很大程度上是一致的，尽管外在肌肉活动的开始通常先于内在肌肉激活的开始。我们的研究结果提供了证据，在体内啮齿动物准备，呼吸调制运动神经元供应内在舌肌。注意到内在和外在活动之间的区别可能是由于运动神经元属性或中央，呼吸相关的控制每个运动神经元人口的差异。
The muscular-hydrostat model of tongue function proposes a constant interaction of extrinsic ( external bony attachment, insertion into base of tongue) and intrinsic ( origin and insertion within the tongue) tongue muscles in all tongue movements (Kier WM and Smith KK. Zool J Linn Soc 83: 207 - 324, 1985). Yet, research that examines the respiratory-related effects of tongue function in mammals continues to focus almost exclusively on the respiratory control and function of the extrinsic tongue protrusor muscle, the genioglossus muscle. The respiratory control and function of the intrinsic tongue muscles are unknown. Our purpose was to determine whether intrinsic tongue muscles have a respiration-related activity pattern and whether intrinsic tongue muscles are coactivated with extrinsic tongue muscles in response to respiratory-related sensory stimuli. Esophageal pressure and electromyographic (EMG) activity of an extrinsic tongue muscle ( hyoglossus), an intrinsic tongue muscle ( superior longitudinal), and an external intercostal muscle were studied in anesthetized, tracheotomized, spontaneously breathing rats. Mean inspiratory EMG activity was compared at five levels of inspired CO2. Intrinsic tongue muscles were often quiescent during eupnea but active during hypercapnia, whereas extrinsic tongue muscles were active in both eupnea and hypercapnia. During hypercapnia, the activities of the airway muscles were largely coincident, although the onset of extrinsic muscle activity generally preceded the onset of intrinsic muscle activation. Our findings provide evidence, in an in vivo rodent preparation, of respiratory modulation of motoneurons supplying intrinsic tongue muscles. Distinctions noted between intrinsic and extrinsic activities could be due to differences in motoneuron properties or the central, respiration-related control of each motoneuron population.