Gora J, Kay A, Colrain I M, Kleiman J, Trinder J
School of Behavioural Science, University of Melbourne, Parkville, Victoria 3052, Australia.
J Appl Physiol (1985). 1998 Jun;84(6):2123-31. doi: 10.1152/jappl.1998.84.6.2123.
Ventilation decreases and airway resistance increases with the loss of electroencephalogram alpha activity at sleep onset. The aim of this study was to determine whether reflexive load compensation is lost immediately on the loss of alpha activity. Six healthy male subjects were studied under two conditions (load and control-no load), in three states (continuous alpha, continuous theta, and immediately after a transition from alpha to theta), and in two phases (early and late sleep onset). Ventilation and respiratory timing were measured. A comparison of loaded with control conditions indicated that loading had no effect on inspiratory minute ventilation during continuous alpha (differential effect of 0.00 l/min) and only a small, nonsignificant effect in theta immediately after phase 2 transitions (0.31 l/min), indicating a preservation of load compensation at these times. However, there were significant decreases in inspiratory minute ventilation on loaded trials during continuous theta in phase 2 (0.77 l/min) and phase 3 (1.15 l/min) and during theta immediately after a transition in phase 3 (0.87 l/min), indicating a lack of reflexive load compensation. The results indicate that, because reflex load compensation is state dependent, state-related changes in airway resistance contribute to state-related changes in ventilation during sleep onset. However, this effect was slightly delayed with transitions into theta early in sleep.
睡眠开始时脑电图α波活动消失，通气量降低，气道阻力增加。本研究的目的是确定α波活动消失时反射性负荷补偿是否立即丧失。对6名健康男性受试者在两种条件下（负荷和对照 - 无负荷）、三种状态（持续α波、持续θ波以及从α波过渡到θ波后即刻）和两个阶段（睡眠开始的早期和晚期）进行了研究。测量了通气量和呼吸时间。负荷条件与对照条件的比较表明，负荷在持续α波期间对吸气分钟通气量无影响（差异效应为0.00升/分钟），在第2阶段过渡后即刻的θ波状态下仅有微小的、无显著意义的影响（0.31升/分钟），这表明此时负荷补偿得以保留。然而，在第2阶段（0.77升/分钟）和第3阶段（1.15升/分钟）的持续θ波期间以及第3阶段过渡后即刻的θ波状态下，负荷试验中的吸气分钟通气量显著降低（0.87升/分钟），这表明缺乏反射性负荷补偿。结果表明，由于反射性负荷补偿取决于状态，睡眠开始期间气道阻力的状态相关变化导致了通气量的状态相关变化。然而，这种效应在睡眠早期向θ波过渡时稍有延迟。
