Ni H, Zhang J, Glotzbach S F, Schechtman V L, Harper R M
Department of Anatomy and Cell Biology, University of California at Los Angeles 90024-1763.
Sleep. 1994 Dec;17(8):657-64. doi: 10.1093/sleep/17.8.657.
Timing and amplitude characteristics of diaphragmatic muscle activity following bilateral local warming of the preoptic area/anterior hypothalamic region (POAH) were studied during sleep in free-moving, intact adult cats. Warming of the POAH increased local brain temperature by 1.4-3.7 degrees C and elicited thermal tachypnea (panting) during quiet sleep (QS). Following transition to rapid eye movement (REM) sleep, the tachypnea, initially induced by warming during QS, diminished, but respiratory rates remained above baseline REM levels, and an intermittent pattern of faster and slower breathing rates developed. In QS, tachypnea resulted primarily from a decline in inspiratory time (TI), whereas in REM sleep, reduction in expiratory time (TE) was more prominent. Although diaphragmatic electromyographic amplitude decreased by 40% during panting in QS, the much higher respiratory rates (+350%) resulted in apparent increases in relative ventilation and inspiratory drive. A less pronounced respiratory rate change (+46%) emerged during REM sleep, resulting in no significant changes in ventilation and inspiratory drive in response to warming in that state. The results suggest that descending thermal influences on respiratory patterning differ between QS and REM states in both overall respiratory rate and on relative TI and TE, and thus do not affect inspiratory drive exclusively.
在自由活动的成年健康猫睡眠期间，研究了视前区/下丘脑前区（POAH）双侧局部升温后膈肌活动的时间和幅度特征。POAH升温使局部脑温升高1.4 - 3.7摄氏度，并在安静睡眠（QS）期间引发热呼吸急促（喘气）。过渡到快速眼动（REM）睡眠后，最初在QS期间由升温诱发的呼吸急促减弱，但呼吸频率仍高于基线REM水平，并且出现了呼吸频率快慢交替的间歇性模式。在QS中，呼吸急促主要源于吸气时间（TI）的缩短，而在REM睡眠中，呼气时间（TE）的缩短更为显著。尽管在QS喘气期间膈肌肌电图幅度下降了40%，但高得多的呼吸频率（+350%）导致相对通气量和吸气驱动力明显增加。在REM睡眠期间出现的呼吸频率变化不太明显（+46%），因此在该状态下升温对通气量和吸气驱动力没有显著影响。结果表明，在总体呼吸频率以及相对TI和TE方面，热对呼吸模式的下行影响在QS和REM状态之间存在差异，因此并非仅影响吸气驱动力。
