ESPCI-ParisTech, Equipe de Statistique Appliquée, F-75005 Paris, France.
UPMC Univ Paris 06, ER 10 UPMC, F-75013 Paris, France; Assistance Publique - Hôpitaux de Paris, Groupe Hospitalier Pitié-Salpêtrière, Service Central d'Explorations Fonctionnelles Respiratoires, F-75013 Paris, France.
Respir Physiol Neurobiol. 2014 Jan 15;191:26-37. doi: 10.1016/j.resp.2013.10.013. Epub 2013 Nov 4.
Central CO(2) chemosensitivity is crucial for all air-breathing vertebrates and raises the question of its role in ventilatory rhythmogenesis. In this study, neurograms of ventilatory motor outputs recorded in facial nerve of premetamorphic and postmetamorphic tadpole isolated brainstems, under normo- and hypercapnia, are investigated using Continuous Wavelet Transform spectral analysis for buccal activity and computation of number and amplitude of spikes during buccal and lung activities. Buccal bursts exhibit fast oscillations (20-30Hz) that are prominent in premetamorphic tadpoles: they result from the presence in periodic time windows of high amplitude spikes. Hypercapnia systematically decreases the frequency of buccal rhythm in both pre- and postmetamorphic tadpoles, by a lengthening of the interburst duration. In postmetamorphic tadpoles, hypercapnia reduces buccal burst amplitude and unmasks small fast oscillations. Our results suggest a common effect of the hypercapnia on the buccal part of the Central Pattern Generator in all tadpoles and a possible effect at the level of the motoneuron recruitment in postmetamorphic tadpoles.
中枢 CO2 化学敏感性对所有空气呼吸的脊椎动物至关重要，这引发了一个问题，即它在通气节律发生中的作用。在这项研究中，使用连续小波变换谱分析对面神经记录的呼吸运动输出的神经图进行了研究，在正常和高碳酸血症下，对面神经记录的呼吸运动输出的神经图进行了研究，用于分析口腔活动，并计算口腔和肺活动期间的尖峰数量和幅度。口腔爆发表现出快速振荡（20-30Hz），在前变形期蝌蚪中很明显：它们是由于在高振幅尖峰的周期性时间窗口中存在而产生的。高碳酸血症系统地降低了前变形和后变形期蝌蚪的口腔节律频率，通过增加爆发间持续时间来实现。在后变形期蝌蚪中，高碳酸血症降低了口腔爆发幅度，并揭示了小的快速振荡。我们的结果表明，高碳酸血症对所有蝌蚪的中枢模式发生器的口腔部分具有共同的影响，并且在后变形期蝌蚪中可能对运动神经元募集水平具有影响。
