颞叶癫痫大鼠认知功能与海马区NR2B表达的关系

目的〓〖HTK〗研究颞叶癫痫大鼠在Morris水迷宫(MWM)中学习、记忆能力与大鼠海马区N-甲基-D-天门冬氨酸受体2亚基B（NR2B）表达变化的关系，探讨颞叶癫痫学习、记忆等认知功能障碍的可能机制。〖HTW〗方法〓〖HTK〗随机将60只Wistar大鼠分为癫痫组（48只）和对照组（12只）。癫痫组采用海人酸（K A）右侧海马立体定向注射制作颞叶癫痫大鼠模型，又分为：癫痫迷宫训练组（A组），癫痫迷宫未训练组（B组）；对照组即NS迷宫训练组（C组），注射生理盐水。通过MWM测验观察A、C组大鼠在7、14、28、42d时各亚组的学习、记忆能力。采用免疫组化法检测大鼠在7、14、28、42d时各亚组海马CA1、CA3区NR2B的表达。〖HTW〗结果〓〖HTK〗与C组相比，在28、42d时A组学习、记忆功能明显下降，相应海马CA1、CA3区NR2B表达均明显降低(P＜0.05，P＜0.01) ，B组在28、42d时海马CA1、CA3区NR2B表达均明显降低(P＜0.01)；与B组相比，A、C组在28、42d时海马CA1、CA3区NR2B表达均增高(P＜0.05，P＜0.01)。与A7、A14d亚组相比，A28、A42d亚组学习、记忆功能逐渐下降(P＜0.05，P＜0.01)，NR2B的表达逐渐降低(P＜0.05，P＜0.01) ，且A组28d与A组42d亚组相比差异有统计学意义(P＜0.05，P＜0.01)。B组各亚组NR2B表达与A组一致。〖HTW〗结论〓〖HTK〗颞叶癫痫长期反复发作时海马区NR2B表达减少，可能是导致颞叶癫痫学习、记忆等认知功能障碍的机制之一。

Cognitive function in temporal lobe rats and the expression of NR2B in the hippocampus

Objective To investigate the abilities of learning and memory in temporal lobe epileptic rats after the Morris water maze(MWM) task training and its relationship with seizure frequency and expression of the N-methyl-D-asparat acid receptor 2B(NR2B).Methods 60 male Wistar rats were randomly divided into the epilepsy group and the control group.The epilepsy models were established by kainic acid(KA) injection into the right hippocampus and the control group(group C) only received normal saline.The epilepsy group was subdivided into group A(epilepsy MWM training group) and group B(epilepsy MWM no-training group).Then learning and memory abilities were tested after MWM training.The expression level of NR2B in the hippocampus was determined by immunohistochemical techniques.Results Compared with the control group,learning and memory abilities of group A were obviously impaired and the expression of NR2B of groups A and B was decreased at 28 and 42 days(P<0.05,P<0.01).Compared with group B,the expression of NR2B of groups A and C was increased at 28 and 42 days(P<0.05,P<0.01).In group A,learning and memory abilities and the expression of NR2B were all decreased by degrees on 28 and 42 days(P<0.05,P<0.01),and the difference was statistical(P<0.05).Group B was similar.Conclusion Thedecrease of NR2B in the hippocampus might result in impairment of learning and memory abilities of temporal lobe epileptic rats.