Worsnop C, Kay A, Pierce R, Kim Y, Trinder J
Department of Respiratory Medicine, Austin and Repatriation Medical Centre, Heidelberg, Victoria 3084, Australia.
J Appl Physiol (1985). 1998 Sep;85(3):908-20. doi: 10.1152/jappl.1998.85.3.908.
Ventilation decreases at sleep onset. This change is initiated abruptly at alpha-theta electroencephalographic transitions. The aim of this study was to determine the contributions of reduced activity in respiratory pump muscles and upper airway dilator muscles to this change. Surface electromyograms over the diaphragm (Di) and intercostal muscles and fine-wire intramuscular electrodes in genioglossus (GG) and tensor palatini (TP) muscles were recorded in nine healthy young men. It was shown that phasic Di and both phasic and tonic TP activities were lower during theta than during alpha activity. Breath-by-breath analysis of the changes at alpha-theta transitions during the sleep-onset period showed a number of changes. At alpha-theta transitions, phasic activity of Di, intercostal, and GG muscles fell and rose again, and phasic and tonic activities of TP fell and remained at low levels during theta. With a state transition from theta to alpha, the phasic and tonic activities of the Di, GG, and TP increased dramatically. It is now clear that the fall in ventilation that occurs with sleep is related to a fall in activities of both upper airway dilator muscles and respiratory pump muscles.
睡眠开始时通气量会下降。这种变化在脑电图从α波向θ波转变时突然开始。本研究的目的是确定呼吸泵肌肉和上气道扩张肌活动减少对这种变化的影响。在9名健康年轻男性中记录了膈肌（Di）和肋间肌表面肌电图以及颏舌肌（GG）和腭帆张肌（TP）的细钢丝肌内电极信号。结果显示，与α波活动期间相比，θ波期间Di的相位活动以及TP的相位和张力活动均较低。对睡眠开始阶段α波向θ波转变时的逐次呼吸变化分析显示出一些变化。在α波向θ波转变时，Di、肋间肌和GG肌的相位活动先下降后又上升，而TP的相位和张力活动下降并在θ波期间维持在低水平。随着从θ波向α波的状态转变，Di、GG和TP的相位和张力活动急剧增加。现在很清楚，睡眠时出现的通气量下降与上气道扩张肌和呼吸泵肌肉的活动减少有关。
