Tiba Paula Ayako, Tufik Sergio, Suchecki Deborah
Department of Psychobiology, Universidade Federal de São Paulo, São Paulo, Brazil.
Physiol Behav. 2008 Feb 27;93(3):444-52. doi: 10.1016/j.physbeh.2007.10.001. Epub 2007 Oct 10.
Early adverse experiences represent risk factors for the development of anxiety and mood disorders. Maternal separation can induce biobehavioral alterations in male rodents similar to those seen in depressed humans, such as hyperresponsiveness to stress and sleep disturbances. Nonetheless, no study has yet explored the effects of early life events on the relationship between stress and sleep in female rats. Whole litters of Wistar rats were submitted to brief- or long maternal separations (15 [BMS] or 180 min/day [LMS], from postnatal days 2-14) or kept undisturbed with their mothers (CTL). When adults, female rats were sleep-recorded for 22 h before (baseline) and after a 1 h exposure to cold stress (post-stress). Additional subsets of animals were sacrificed before, 1 or 3 h after the stressor for plasma corticosterone determination. No differences in baseline sleep were observed among the groups. Female rats submitted to LMS exhibited a significant increase of REM sleep on the night following a 1 h exposure to cold stress, whereas the sleep of BMS rats was barely altered by stress. All groups exhibited similar basal and stress-induced corticosterone levels. The present results are compared to a previous study performed in male rats, and corroborate that manipulations applied during infancy modify the expression of stress-induced sleep rebound.
早期不良经历是焦虑和情绪障碍发展的风险因素。母婴分离可在雄性啮齿动物中诱发生物行为改变，类似于在抑郁症患者中观察到的改变，如对应激的高反应性和睡眠障碍。然而，尚无研究探讨早期生活事件对雌性大鼠应激与睡眠关系的影响。将整窝Wistar大鼠进行短期或长期母婴分离（出生后第2 - 14天，每天15分钟[短期母婴分离]或180分钟[长期母婴分离]），或与母亲一起不受干扰（对照组）。成年后，对雌性大鼠在暴露于冷应激1小时前（基线）和后进行22小时睡眠记录。在应激源前、应激源后1或3小时处死另外几组动物以测定血浆皮质酮。各组之间在基线睡眠方面未观察到差异。经历长期母婴分离的雌性大鼠在暴露于冷应激1小时后的夜间快速眼动睡眠显著增加，而短期母婴分离大鼠的睡眠几乎未因应激而改变。所有组的基础和应激诱导的皮质酮水平相似。将本研究结果与之前在雄性大鼠中进行的一项研究进行比较，证实婴儿期进行的操作会改变应激诱导的睡眠反弹的表现。
