Haxhiu M A, van Lunteren E, Mitra J, Cherniack N S
J Appl Physiol Respir Environ Exerc Physiol. 1984 Feb;56(2):397-403. doi: 10.1152/jappl.1984.56.2.397.
The steady-state and transient effects of hyperoxic hypercapnia on the electromyographic activities of the genioglossus (GG), posterior cricoarytenoid (PCA), and diaphragm (D) were studied in conscious unsedated cats with chronically implanted electrodes. Hypercapnia (inhalation of 3.4 and 7.4% CO2 in O2) increased the phasic electrical activity occurring during inspiration in all three muscles and also increased tonic activity of the GG. The GG responded to steady-state CO2 inhalation alinearly and with larger increases in activity than the PCA and D. Phasic GG activity was present in only 4 of 10 cats breathing 100% O2, whereas phasic PCA and D activity could be observed in all animals studied. When gas mixtures containing CO2 were given, the GG reached its new steady-state level more slowly than the D or PCA, and when CO2 was rapidly removed from the inspired gas mixture, the GG attained its steady state sooner than either the PCA or D. These results suggest that in awake unsedated animals, chemical stimuli do not affect either transient or steady-state responses of the GG in the same way as the D. These differences seem to be explained mainly by different threshold characteristics of hypoglossal and phrenic neurons but also in part by dissimilarities in their steady-state responses.
在长期植入电极的清醒未麻醉猫中，研究了高氧高碳酸血症对颏舌肌（GG）、环杓后肌（PCA）和膈肌（D）肌电图活动的稳态和瞬态影响。高碳酸血症（吸入含3.4%和7.4%二氧化碳的氧气）增加了所有三块肌肉在吸气时出现的相位电活动，也增加了颏舌肌的紧张性活动。颏舌肌对稳态二氧化碳吸入的反应呈非线性，且活动增加幅度大于环杓后肌和膈肌。在呼吸100%氧气的10只猫中，只有4只出现了颏舌肌的相位活动，而在所有研究动物中都能观察到环杓后肌和膈肌的相位活动。当给予含二氧化碳的混合气体时，颏舌肌达到新稳态水平的速度比膈肌或环杓后肌慢，而当从吸入混合气体中迅速去除二氧化碳时，颏舌肌比环杓后肌或膈肌更快达到稳态。这些结果表明，在清醒未麻醉的动物中，化学刺激对颏舌肌瞬态或稳态反应的影响与膈肌不同。这些差异似乎主要由舌下神经和膈神经神经元的不同阈值特性解释，但部分也由它们稳态反应的差异解释。
