Department of Psychology, Purdue School of Science, Indiana University-Purdue University, Indianapolis, IN 46202, USA.
Psychopharmacology (Berl). 2011 Nov;218(1):157-67. doi: 10.1007/s00213-011-2381-6. Epub 2011 Jun 25.
Swim test susceptible (SUS) rats selectively bred for reduced struggling in the forced swim test (FST) following stress show high voluntary ethanol intake like alcohol-preferring (P) rats selectively bred for ethanol preference. It is unknown whether stress enhances drinking in SUS rats or FST behavior in P and non-preferring (NP) rats.
The aim of this study was to assess the response to stress in male SUS, Sprague-Dawley (SD), P, and NP rats on 10% ethanol drinking and FST behavior.
In experiment 1, SUS and SD rats had limited access to ethanol and water following white noise, rehousing, and forced swim stress. In experiment 2, P and NP rats received footshock, white noise, restraint, or no stress prior to the FST. Rats then had continuous access to ethanol and water, and the effects of weekly exposures to stress were measured.
SUS rats drank more ethanol (M = 2.98 g/kg) than SD rats (M = 1.26 g/kg) at baseline. Stress produced sustained increases (33% of baseline) in ethanol intake in SUS rats. NP rats spent twice as much time immobile as P rats in the FST. Stress did not alter FST behavior in P or NP rats. Only footshock produced an increase (29%) in ethanol intake in P rats.
Selection for stress-induced depressive-like behavior in SUS rats is associated with enhanced stress-induced ethanol drinking. However, the selection for alcohol preference is not associated with stress-induced depressive-like behavior but is associated with footshock stress-induced ethanol drinking. In these experiments, relationships among stress, depressive-like behavior, and alcohol preference were not symmetrical.
经过压力选择培育后，在强迫游泳试验（FST）中挣扎减少的游泳试验易感（SUS）大鼠与选择性培育的酒精偏好（P）大鼠一样，表现出高的自愿性乙醇摄入。目前尚不清楚压力是否会增强 SUS 大鼠的饮酒行为，或 FST 行为是否会增强 P 和非偏好（NP）大鼠的饮酒行为。
本研究旨在评估雄性 SUS、Sprague-Dawley（SD）、P 和 NP 大鼠在 10%乙醇摄入和 FST 行为方面对压力的反应。
在实验 1 中，SUS 和 SD 大鼠在白噪声、重新安置和强迫游泳应激后，可有限地接触乙醇和水。在实验 2 中，P 和 NP 大鼠在 FST 之前接受足部电击、白噪声、束缚或无应激。然后，大鼠持续接触乙醇和水，并测量每周暴露于应激的影响。
SUS 大鼠的基线乙醇摄入量（M=2.98 g/kg）高于 SD 大鼠（M=1.26 g/kg）。应激持续增加 SUS 大鼠的乙醇摄入量（约基线的 33%）。NP 大鼠在 FST 中不动的时间是 P 大鼠的两倍。应激未改变 P 或 NP 大鼠的 FST 行为。只有足部电击可增加 P 大鼠的乙醇摄入量（约 29%）。
SUS 大鼠应激诱导的抑郁样行为选择与增强的应激诱导的乙醇摄入有关。然而，酒精偏好的选择与应激诱导的抑郁样行为无关，但与足部电击应激诱导的乙醇摄入有关。在这些实验中，应激、抑郁样行为和酒精偏好之间的关系不对称。
