电针对吗啡戒断大鼠学习记忆和VTA脑区CaMKⅡ含量的影响

Effect of Electroacupuncture on Learning and Memory and Brain VTA CaMKⅡ Content in Morphine Withdrawal Rats

目的研究电针对吗啡戒断大鼠空间学习记忆能力及对中脑腹侧被盖区(ventral tegmental area,VTA)记忆分子钙/钙调素依赖性蛋白激酶Ⅱ(CaMKⅡ)的活性影响。方法采用逐日递增法背部皮下注射吗啡5 d,造成吗啡依赖,给予纳洛酮催促,建立吗啡戒断大鼠模型。采用Morris水迷宫操作方法训练大鼠,测试其空间学习记忆能力;免疫组化法测定各组大鼠VTA脑区CaMKⅡ的活性表达。结果电针组大鼠平台逃避潜伏期较模型组明显缩短(P<0.01);电针组与模型组比较显著增加穿越平台次数(P<0.01);电针组CaMKⅡ的平均光密度值显著高于模型组(P<0.01);电针组和艾灸组比较差异有统计学意义(P<0.05)。结论电针和艾灸治疗均可改善吗啡戒断后大鼠空间学习和记忆能力,电针组疗效更显著;可能与吗啡戒断后VTA脑区CaMKⅡ的含量增加有关。

Objective To investigate the effect of electroacupuncture on spatial learning ability and memory and mesencephalic ventral tegmental area（VTA） memory molecule Ca2＋-calmodulin-dependent protein kinaseⅡ（CaMKⅡ） activity in morphine withdrawal rats.Method A rat model of morphine withdrawal was made by dorsal subcutaneous injections of day-by-day incremental morphine for 5 consecutive days to cause morphine addiction and administering naloxone to promote withdrawal.The rats were trained for orientation in a Morris water maze.Their spatial learning ability and memory were tested.The expression of CaMKⅡ activity in encephalic VTA was determined by immunohistochemical method in each group of rats.Result The platform escape latency was significantly shorter in the electroacupuncture group of rats than in the model group（P0.01）.The frequency of crossing the platform increased significantly in the acupuncture group compared with the model group（P0.01）.The mean optical density value of CaMKⅡ was significantly higher in the electroacupuncture group than in the model group（P0.01）.There was a statistically significant difference between the electroacupuncture and moxibustion groups（P0.05）.Conclusion Both electroacupuncture and moxibustion can improve spatial learning ability and memory in morphine withdrawal rats.The therapeutic effect is more marked in the electroacupuncture group.It may be related to an increase in brain VTA CaMKⅡ content after morphine withdrawal.