Centre de Recherche du CHUQ, Hôpital St-François d'Assise, Université Laval, Québec, Canada.
Sleep. 2009 Dec;32(12):1611-20. doi: 10.1093/sleep/32.12.1611.
Neonatal maternal separation (NMS) disrupts development of cardiorespiratory regulation. Adult male rats previously subjected to NMS are hypertensive and show a hypoxic ventilatory response greater than that of controls. These results have been obtained in awake or anesthetised animals, and the consequences of NMS on respiratory control during normal sleep are unknown. This study tested the following.
NMS augments respiratory variability across sleep-wake states, and NMS-related enhancement of the hypoxic ventilatory response occurs during sleep.
Two groups of adult rats were used: controls (no treatment) and rats subjected to NMS. Ventilatory activity, coefficient of variation, and hypoxic ventilatory response were compared between groups and across sleep-wake states.
Male Sprague Dawley rats-NMS: n=11; controls: n=10. Pups subjected to NMS were isolated from their mother for 3 hours per day from postnatal days 3 to 12. Controls were undisturbed.
At adulthood, sleep-wake states were monitored by telemetry, and ventilatory activity was measured using whole-body plethysmography. Sleep and breathing were measured for 2.5 hours (in the morning) while the rats were breathing room air. Data were analysed in 20-second epochs. Rats were then exposed to a brief (90-sec) hypoxic episode (nadir = 12% O2) to measure the hypoxic ventilatory response. The coefficient of variability for tidal volume and breathing frequency decreased during sleep but remained more elevated in NMS rats than in controls. During non-rapid eye movement sleep, the breathing-frequency response to hypoxia of NMS rats was significantly greater than that of controls.
Neonatal maternal separation results in persistent disruption of respiratory control during sleep.
新生儿母婴分离（NMS）会破坏心肺调节的发育。先前经历过 NMS 的成年雄性大鼠表现出高血压，并且其低氧通气反应大于对照。这些结果是在清醒或麻醉动物中获得的，并且 NMS 对正常睡眠期间呼吸控制的影响尚不清楚。本研究检验了以下假设。
NMS 会增加睡眠-觉醒状态下的呼吸变异性，并且 NMS 相关的低氧通气反应增强发生在睡眠期间。
使用两组成年大鼠：对照组（未处理）和 NMS 组。比较两组和睡眠-觉醒状态之间的通气活动、变异系数和低氧通气反应。
雄性 Sprague Dawley 大鼠-NMS：n=11；对照组：n=10。NMS 组的幼鼠从出生后第 3 天到第 12 天，每天与母亲分离 3 小时。对照组不受干扰。
成年后，通过遥测监测睡眠-觉醒状态，并使用全身 plethysmography 测量通气活动。在大鼠呼吸室内空气的情况下，监测 2.5 小时（上午）的睡眠和呼吸。数据以 20 秒为一个时间段进行分析。然后，大鼠暴露于短暂（90 秒）的低氧期（最低点= 12% O2）以测量低氧通气反应。潮气量和呼吸频率的变异系数在睡眠期间降低，但在 NMS 大鼠中仍高于对照组。在非快速眼动睡眠期间，NMS 大鼠的呼吸频率对低氧的反应明显大于对照组。
新生儿母婴分离导致睡眠期间持续的呼吸控制障碍。
