海马氨基酸参与调控运动性疲劳大鼠学习记忆能力及海马CA1、CA3区c-fos的表达

Hippocampus Amino Acid Is Involved In Regulating the Learning and Memory and C-fos Expression within Hippocampus CA1、CA3 in the Fatigue Training Rats

目的:观察疲劳训练对大鼠学习记忆能力、海马氨基酸含量及海马CA1、CA3区c-fos表达的影响,探讨疲劳训练降低大鼠学习记忆能力的可能机制。方法:将30只SD大鼠(3月龄)随机分为对照组、有氧训练组及疲劳训练组,有氧训练组采用中等负荷跑台运动,疲劳训练组采用递增负荷疲劳训练,连续8周。8周训练结束后,第2天利用水迷宫实验测试大鼠空间学习记忆能力,水迷宫行为测试结束后,即刻检测大鼠海马氨基酸含量,采用免疫组织化学结合图像半定量方法对海马CA1、CA3区c-fos神经元表达进行测量和分析。结果:(1)与对照组比较,有氧训练组及疲劳训练组大鼠海马谷氨酸含量均增高(P<0.05,P<0.01),有氧训练组大鼠GABA含量与对照组的差异无统计学意义(P>0.05),Glu/GABA比值显著增高(P<0.05),疲劳训练组大鼠GABA含量显著增多(P<0.01),Glu/GABA比值降低(P<0.05);(2)与对照组比较,有氧训练组大鼠逃避潜伏期缩短(P<0.05),穿越平台次数增多(P<0.05),而疲劳训练组大鼠逃避潜伏期延长(P<0.01),穿越平台次数减少(P<0.05);(3)8周跑台运动后,有氧训练组及疲劳训练组大鼠CA1、CA3区c-fos神经元的数量及面积均较对照组明显增加(P<0.05,P<0.01)。结论:海马谷氨酸过度分泌导致CA1、CA3区c-fos神经元过度表达,可能参与了运动疲劳导致的大鼠学习记忆能力的下降。

Objective： Observing the influence of fatigue training on learning and memory, Hippocampal amino acid content and c-fos expression in the Hip- pocampus CA1, CA3 of the fatigue training rats and inquiring into the mechanism of the fatigue training decreasing learning and memory. Methods： 30 SD rats （3 months） were chosen and randomly divided into 3 groups, which included control group （C）, aerobic training group （AT） and fatigue training group （FT）. The C group rats kept normal activities, AT group rats undertook a 8-week moderate-load treadmill training and FT group rats undertook a 8-week fa- tigue training with progressively increasing load. The morris water maze test was used to assess each animal＇s capability of learning and memory the next day after 8-week treadmill training, then hippocampal amino acid content were examined, c-fos expression in hippocampus CA1, CA3 was detected and analyzed by using ABC immuneohistochemical technique and semi quantitative. Results： （1） Compared with the C group, Glu content in hippocampal significantly in- creased （P〈0.05, P〈0.01 ） in the AT and FF group rats; GABA content in hippocampal was not significant difference （P〉0.05） and the ratio of Glu/GABA in- creased in AT group rats; GABA content and the ratio of Glu/GABA in hippocampal significantly increased （P〈O.O5,P〈O.O1） in FT group rats when compared to the C group rats.（2） Compared with the C group, escape latency shortened（P〈O.05）, the times across platform increased（P〈0.05） in AT group rats, but es- cape latency extened （P〈0.01 ） and the times across platform decreased （P〈0.05） in FT group rats;（3 ） Compared with the C group, the number and area of c- fos in hippocampus CA1 ,CA3 notably increased in the AT and FT group rats （P〈O.O5,P〈O.O1）. Conclusion： Glu over secretion in hippocampus causing c-fos over expression in hippocampus CA1, CA3 may contribute to the learning and memory declining in fatigue training rats.