Texas Tech University Health Sciences Center School of Medicine, Department of Cell Physiology and Molecular Biophysics, Lubbock TX, USA.
Sleep. 2011 Apr 1;34(4):425-34. doi: 10.1093/sleep/34.4.425.
In this study, we quantified the profiles of phasic activity in respiratory muscles (diaphragm, genioglossus and external intercostal) and non-respiratory muscles (neck and extensor digitorum) across REM sleep. We hypothesized that if there is a unique pontine structure that controls all REM sleep phasic events, the profiles of the phasic twitches of different muscle groups should be identical. Furthermore, we described how respiratory parameters (e.g., frequency, amplitude, and effort) vary across REM sleep to determine if phasic processes affect breathing.
Electrodes were implanted in Wistar rats to record brain activity and muscle activity of neck, extensor digitorum, diaphragm, external intercostal, and genioglossal muscles. Ten rats were studied to obtain 313 REM periods over 73 recording days. Data were analyzed offline and REM sleep activity profiles were built for each muscle. In 6 animals, respiratory frequency, effort, amplitude, and inspiratory peak were also analyzed during 192 REM sleep periods.
Respiratory muscle phasic activity increased in the second part of the REM period. For example, genioglossal activity increased in the second part of the REM period by 63.8% compared to the average level during NREM sleep. This profile was consistent between animals and REM periods (η(2)=0.58). This increased activity seen in respiratory muscles appeared as irregular bursts and trains of activity that could affect rythmo-genesis. Indeed, the increased integrated activity seen in the second part of the REM period in the diaphragm was associated with an increase in the number (28.3%) and amplitude (30%) of breaths. Non-respiratory muscle phasic activity in REM sleep did not have a profile like the phasic activity of respiratory muscles. Time in REM sleep did not have an effect on nuchal activity (P=0.59).
We conclude that the concept of a common pontine center controlling all REM phasic events is not supported by our data. There is a drive in REM sleep that affects specifically respiratory muscles. The characteristic increase in respiratory frequency during REM sleep is induced by this drive.
在这项研究中，我们量化了呼吸肌（膈肌、颏舌肌和肋间外肌）和非呼吸肌（颈部和伸趾肌）在 REM 睡眠期间的相位活动谱。我们假设，如果存在一个控制所有 REM 睡眠相位事件的独特脑桥结构，那么不同肌肉群的相位抽搐模式应该是相同的。此外，我们描述了呼吸参数（如频率、幅度和努力）如何在 REM 睡眠期间变化，以确定相位过程是否会影响呼吸。
将电极植入 Wistar 大鼠，以记录颈部、伸趾肌、膈肌、肋间外肌和颏舌肌的脑电活动和肌肉活动。对 10 只大鼠进行研究，在 73 个记录日中获得 313 个 REM 期。离线分析数据，并为每个肌肉构建 REM 睡眠活动谱。在 6 只动物中，还在 192 个 REM 睡眠期间分析了呼吸频率、努力、幅度和吸气峰。
呼吸肌的相位活动在 REM 周期的第二部分增加。例如，与 NREM 睡眠期间的平均水平相比，颏舌肌的活动在 REM 周期的第二部分增加了 63.8%。这种模式在动物和 REM 周期之间是一致的（η²=0.58）。在 REM 周期的第二部分，呼吸肌中看到的这种增加的活动表现为不规则的爆发和活动串，可能会影响节律发生。事实上，在 REM 周期的第二部分，膈肌中观察到的整合活动增加与呼吸次数的增加（28.3%）和幅度的增加（30%）有关。REM 睡眠中非呼吸肌的相位活动没有像呼吸肌的相位活动那样的模式。REM 睡眠时间对颈部活动没有影响（P=0.59）。
我们的结论是，一个共同的脑桥中心控制所有 REM 相位事件的概念没有得到我们数据的支持。在 REM 睡眠中有一个驱动力，专门影响呼吸肌。REM 睡眠期间呼吸频率的特征性增加是由这种驱动力引起的。
