Co-activation of tongue protrudor and retractor muscles during chemoreceptor stimulation in the rat
Co-activation of tongue protrudor and retractor muscles during chemoreceptor stimulation in the rat
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DOI：
10.1111/j.1469-7793.1998.265bu.x
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发表时间：
1998-02-15
影响因子：
5.5
通讯作者：
Fregosi, RE
中科院分区：
文献类型：
--
作者：
Fuller, D;Mateika, JH;Fregosi, RE
1. 我们的主要目的是检验这样的假设：当呼吸动力增加时，伸舌肌（颏舌肌，GG）和牵舌肌（茎舌肌，SG 和舌舌肌，HG）共同激活，并且共同激活将导致舌头回缩。通过使用仰卧、麻醉、气管切开的大鼠进行两个系列的实验来解决这个问题，其中可以在自主呼吸期间测量舌肌力以及对前伸肌和牵缩肌的神经驱动。在第一个系列的实验中，通过闭塞气管插管三十个呼吸周期来逐渐增加呼吸动力；在第二组实验中，动物处于高氧高碳酸血症和异二氧化碳性缺氧状态。 2．三十次呼吸的气道阻塞引起了伸舌肌和缩舌肌的传出运动神经活动的渐进性、定量相似的增加。舌肌净力始终与咬合过程中的舌头回缩一致，峰值力与神经活动平行上升。当在第 XII 侧神经分支部分（牵开肌去神经支配）之后重复气道闭塞时，舌头要么伸出（15/21 动物；第 30 次闭塞呼吸时 10 +/- 2 mN），要么微弱地缩回（6/21 动物；第 30 次闭塞呼吸时 6 +/- 2 mN）。3。为了确保我们的发现不是肌肉神经损伤的结果，还在八只动物中进行了闭塞实验，记录了 GG EMG 活动而不是神经活动。咬合期间峰值积分 GG 肌电图 (EMG) 活动和峰值回缩力的变化高度相关 (r(2) = 0.86，斜率 = 1.05)。4。在十四只大鼠的单独实验中，我们发现高氧高碳酸血症和低碳酸血症也会导致 GG 和 KG 肌肉的呼吸相关肌电图活动平行增加。此外，正如在咬合实验中一样，突出肌和牵缩肌肌电图活动的增强与舌头牵拉力的平行变化相关。5．这些对麻醉大鼠的研究表明，气管闭塞和中枢或外周化学感受器的独立刺激导致吸气相关的前伸肌和牵缩肌的共同激活，以及舌头回缩力的成比例变化。这些观察结果还表明，单独记录 GG EMG 活动可能会导致关于舌头呼吸相关运动的错误结论。
1. Our primary purpose was to test the hypothesis that the tongue protrudor (genioglossus, GG) and retractor (styloglossus, SG and hyoglossus, HG) muscles are co-activated when respiratory drive increases, and that co-activation will cause retraction of the tongue. This was addressed by performing two series of experiments using a supine, anaesthetized, tracheotomized rat in which tongue muscle force and the neural drive to the protrudor and retractor muscles could be measured during spontaneous breathing. In the first series of experiments, respiratory drive was increased progressively by occluding the tracheal cannula for thirty respiratory cycles; in the second series of experiments, the animals were subjected to hyperoxic hypercapnia and poikilocapnic hypoxia.2. Airway occlusion for thirty breaths caused progressive, quantitatively similar increases in efferent motor nerve activity to protrudor and retractor tongue muscles. Net tongue muscle force was always consistent with tongue retraction during occlusion, and peak force rose in parallel with the neural activities. When airway occlusion was repeated following section of the lateral XIIth nerve branch (denervation of retractor muscles) the tongue either protruded (15/21 animals; 10 +/- 2 mN at the 30th occluded breath) or retracted weakly (6/21 animals; 6 +/- 2 mN at 30th occluded breath).3. To ensure that our findings were not the result of damage to the muscle nerves, occlusion experiments were also done in eight animals in which GG EMG activity was recorded instead of nerve activities. Changes in peak integrated GG electryomyogram (EMG) activity and peak retraction force during occlusion were highly correlated (r(2) = 0.86, slope = 1.05).4. In separate experiments in fourteen rats, we found that hyperoxic hypercapnia and poikilocapnic hypoxia also result in parallel increases in the respiratory-related EMG activity of the GG and KG muscles. Also, as in the occlusion experiments, augmentations of protrudor and retractor muscle EMG activities were associated with parallel changes in tongue retraction force.5. These studies in anaesthetized rats demonstrate that tracheal occlusion and independent stimulation of central or peripheral chemoreceptors results in inspiratory-related coactivation of the protrudor and retractor muscles, and proportional changes in tongue retraction force. These observations also demonstrate that recording GG EMG activity in isolation could lead to erroneous conclusions about respiratory-related movements of the tongue.