Objective: This study was designed to examine whether enriched environments (EE) would attenuate object recognition and spatial learning and memory deficits and locomotor sensitization induced by methadone maintenance treatment (MMT) in morphine-withdrawn rats. Methods: Male Wistar rats (170 ± 10 g) were injected with bi-daily doses (10 mg/kg, 12-h intervals) of morphine for 14 days. Rats receiving MMT were reared in the standard environment (SE) or EE during 30 days of morphine withdrawal. Then, the rats were tested for object recognition (the object recognition memory test, ORMT) and spatial learning and memory (the water maze) and then challenged with morphine (1 mg/kg, i.p.) and evaluated for locomotor activity (open-field box). Results: The results revealed that the dependent/saline/EE (D/Sal/EE) and D/methadone/EE (D/Meth/EE) rats exhibited significant preference for the new object (p = 0.006 and p = 0.049), spent more time in the target zone (p = 0.045 and p = 0.005) on the water maze, and displayed a lower level of distance traveled (p = 0.002 and p = 0.0001) compared to their control groups reared in SE. Conclusions: We conclude that exposure to EE could ameliorate the object recognition and spatial memory deficits and also decrease locomotor sensitivity in morphine-withdrawn rats receiving MMT. Thus, EE may be beneficial in the treatment of addiction during MMT.
Neuropsychobiology

中文翻译：

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丰富的环境改善接受美沙酮维持治疗的吗啡戒断大鼠的认知缺陷和运动敏感

目的：本研究旨在检查丰富环境 (EE) 是否会减弱吗啡戒断大鼠由美沙酮维持治疗 (MMT) 引起的物体识别和空间学习记忆缺陷和运动致敏。方法：雄性 Wistar 大鼠 (170 ± 10 g) 每天两次注射吗啡（10 mg/kg，间隔 12 小时），持续 14 天。接受 MMT 的大鼠在吗啡戒断 30 天期间在标准环境 (SE) 或 EE 中饲养。然后，测试大鼠的物体识别（物体识别记忆测试，ORMT）和空间学习和记忆（水迷宫），然后用吗啡（1 mg/kg，ip）挑战并评估运动活动（开放场盒子）。结果：结果显示，依赖/盐水/EE（D/Sal/EE）和D/美沙酮/EE（D/Meth/EE）大鼠对新对象表现出显着的偏好（p = 0.006和p = 0.049），花费更多水迷宫上目标区域的时间（p = 0.045 和p = 0.005），与在 SE 中饲养的对照组相比，显示出较低水平的行进距离（p = 0.002 和p = 0.0001）。结论：我们得出结论，暴露于 EE 可以改善接受 MMT 的吗啡戒断大鼠的物体识别和空间记忆缺陷，并降低运动敏感性。因此，EE 可能有助于治疗 MMT 期间的成瘾。
神经心理生物学