【摘要】 目的 :观察电针对吗啡戒断大鼠学习记忆能力及海马外侧穿通纤维CA3区直接传导通路长时程增强 (LTP)损害的恢复作用 ,并探讨其机制。方法 :慢性腹腔注射吗啡建立SD大鼠吗啡依赖模型。在“足三里”和“三阴交”两穴位处给予吗啡依赖和戒断大鼠多次和单次电针治疗 ,并测试学习记忆能力 ,记录CA3区群体峰电位 ,及观察高频刺激引起的LTP效应。结果 :吗啡戒断大鼠学习记忆能力和LTP效应均受损 ,单次电针治疗对其有一定恢复作用 ,多次电针治疗能完全恢复被损害的学习记忆能力和LTP ,电针效应能被阿片受体抑制剂纳络酮所阻断。结论 :电针穴位通过内源性阿片系统调制吗啡戒断大鼠的突触可塑性。更多还原

【Abstract】 Objective: To determine if chronic morphine treatm ent affects the rat’s learni ng-memory ability and the induction of long-term potentiation (LTP) of hippoca mpal CA3 region, and to examine if electroacupuncture (EA) can improve learning -memo ry and LTP in morphine-dependent rats. Methods: 64 SD rats wer e randomized into co ntrol, morphine-abstinence model, EA-one-session and EA-multi-session grou ps. Mo rphine-abstinence model was established by i.p. of hydrochloride morphine. EA ( 2 Hz, 1～3 mA, 30 min) was applied to bilateral “Zusanli”(ST 36) and “Sany injiao”( SP 6), once and multiple times. The rats’ passive and active avoidance reaction s in a compartment equipped with a grid floor through which an electric shock (40 V) was delivered were used as the indexes of learning-memory. The population spi ke (PS) was recorded from pyramidal cells of CA3 in vivo, following stimulation of lateral perforant path in control and morphine-abstinence rats. For the ind uc tion of LTP, 4 trains (50 shocks/train, 500 Hz) high-frequency tetanic stimula tio ns were applied to lateral perforant path. Results: Results i ndicated that the attack times of morphine withdrawal syndrome of EA-one-session group at 24 h and EA-multi-session group at 24 h, 48 h and 72 h times were significantly fewer than t hose of morphine-abstinence model group (P<0.05). Passive expe riments displayed that the latency values of platform leaving of EA-one-session and EA-multi- sessi on groups were significantly shorter than that of model group (P<0.05). Results of active avoidance experiments indicated that the avoidance-reaction correct r at es of EA-multi-session group on the 1st , 2nd, 3rd days were significantly higher than those of model group , showing an improvement of learning-memory after acupunc tu re. In model group, the amplitude of tetanic stimulation induced PS potential w as attenuated significantly in comparison with that of control group, and those of EA-one-session and EA-multi-session groups were higher than that of mode l gro up, suggesting that EA could reverse morphine induced harmful influence on LTP a nd better synaptic transmission of hippocampal neurons. Local application of naloxone to CA3 area, the effect of EA on LTP was inhibited significantly, sugge sting an involvement of opium system in the therapeutic effect of EA. C onclusion:EA can improve morphine- induced lesion of learning-memory and modulate the sy naptic plasticity of neurons in perforant path- CA3 in morphine-dependent rats, a nd the effect of EA may be mediated by the endogenous opium system.更多还原