高脂饲养青春期大鼠电击回避反应和海马CA3区场电位的改变

The changes of electric shock avoidance response and local field potentials on hippocampal CA3 region of the adolescent rats with high fat feeding

目的：观察高脂饲养至青春期的大鼠对电击回避反应和海马CA3区实时局部场电位变化。方法：断乳1周幼鼠改用基础饲料和高脂饲料分别喂养4周至青春期,分为基础饲料组（BF组）和高脂饲料组（HFD组）,Y型迷宫电击回避训练方法,记录2组大鼠电击回避达学会标准的相关参数,同时无线遥测大鼠达标时海马CA3区实时局部场电位。结果：与BF组大鼠比较,HFD组大鼠体重明显增加,Y型迷宫电击回避训练1-2 d大鼠达标百分率、电击回避达标各项指标均略优于BF组;双侧海马CA3区局部场电位节律出现去同步化快波改变,右侧海马CA3区出现了θ波和γ1波百分比的同步性增加,但无θ-γ1波相位-振幅耦合出现。结论：幼年期短期高脂饮食至青春期的大鼠,尽管体重较基础饲料大鼠增加,但未见Y型迷宫电击回避反应能力和海马依赖性空间认知功能的减退。

Objective： To investigate the changes of shock avoidance response in Y maze and the real-time local field potentials（ LFPs） on hippocampal CA3 region in adolescent rats with high fat feeding. Methods： The juvenile rats of weaning 1 week were fed separately on basic feed（ BF） and high fat diet（ HFD） for 4 weeks until the puberty. Using the electric shock avoidance training method,the relevant parameters of reaching the learning standard of two groups of rats were recorded,and the LFPs of CA3 region in hippocampus were explored simultaneously by wireless telemetry. Results： Compared with the BF group,the body weight of HFD rats were increased significantly（ P 0.05）,the rats percentage of reaching the learning standard within 1 to 2 days and the various parameters of shock avoidance recorded in training were all superior to those of BF group rat,the LFP rhythm of bilateral hippocampal CA3 region appeared to the desynchronizd fast wave. The θ andγ1 rhythms of right hippocampal CA3 region shown synchronous increase,but there was no coupling formation in phase-amplitude of the θ and γ1rhythms. Conclusion： From juvenile to adolescent with HFD intake,the adolescent rat gained an increase significantly in weight,but the ability of shock avoidance and the function of hippocampus-dependent spatial cognition in Y maze had not be expected decline.