大鼠脑损伤后NMDAR1表达及其认知障碍变化的关系

Relationship of expressions of NMDAR1 and cognitive impairment after traumatic brain injury in rats

目的同步考量脑损伤后大鼠与认知功能较为密切的脑区N-甲基-D-天冬氨酸受体1(NMDAR1)表达与认知功能的变化。方法参照Feeney法建立大鼠创伤性脑损伤模型,伤后1 d,2 d,4 d,7 d以免疫组化SABC法检测大鼠额叶皮质、海马区、基底前脑区NMDAR1表达,以行走实验、平衡实验及记忆功能测定评估大鼠认知障碍变化。结果轻、中型脑损伤组大鼠于伤后2d认知障碍最严重,分别于伤后3,7 d基本恢复正常。轻型、中型脑损伤组脑额叶皮质、海马区、基底前脑区NMDAR1均于伤后1d升高,于2 d降至较低水平后再呈缓慢增高趋势,与认知障碍变化趋势呈同步变化,且中型脑损伤组NMDAR1表达高于假手术组与轻型脑损伤组(P<0.05)。结论大鼠经创伤性脑损伤后,额叶皮质、海马区、基底前脑区细胞中的NMDAR1含量和损伤后认知障碍的变化趋势有相似性;创伤性脑损伤后表达增加的NMDAR1对大鼠认知功能有加重损害作用。

Objective To observe the relationship between the cognitive impairment and the expression of NMDAR1 in the cortex of frontal lobe, hippocampus and basal forebrain. Methods Based on Feeney＇ s model of TBI,the brain tissue samples were taken at 1 d,2d,4d,7d respectively after brain injury. The expression of NMDAR1 was examined by immunohistochemical SABC approach and compared with sham-operation control group. Results In the brain of sham-operation control group, the low expression level of NMDAR1 was observed. The expression of NMDAR1 at 1 d after injury was higher than the sham-operation control group and returned to basal level at 2d. The test results of the learning and memory is adopt of the change. Conclusion The results suggest that the expression of NMDAR1 decreases following cognitive impairment, and NMDAR1 synthesized by the brain itself may play an important protective role in cognitive function of the brian.