脑震荡大鼠认知行为障碍及多巴胺能神经元的变化  

Cognitive behavioral deficits and changes of dopaminergic neuron after brain concussion in rats

作　　者：吴春云[1] 郭泽云[1] 于建云[2] 林海英[2] 杨力[1] 许冰莹[2] 李坪[1] 赵旭东[3] 

机构地区：[1]昆明医学院组织胚胎学教研室,650031 [2]昆明医学院法医学院 [3]昆明医学院精神病学教研室

出　　处：《中华创伤杂志》2007年第4期279-283,共5页Chinese Journal of Trauma

基　　金：国家自然科学基金资助项目（30160027,30560041）;云南省教育厅基金资助项目（5Z0509C）

摘　　要：目的　探讨脑震荡大鼠认知障碍的特征及多巴胺能神经元的变化。方法　用金属单摆打击装置复制大鼠单纯性脑震荡模型。随机分为伤后1，2，4，8，16，24d六个损伤组和对照组（各12只）；应用Morris水迷宫评价大鼠的学习记忆功能；用免疫组织化学方法研究中脑黑质致密区（SNC）和腹侧被盖区（VTA）多巴胺能神经元的变化。结果　8d组脑震荡后1～3d大鼠隐匿平台逃避潜伏期显著延长（P〈0，05），16d组和24d组水迷宫实验与对照组比较，差异无统计学意义。SNC和VTA的神经元酪氨酸羟化酶在伤后各组均不同程度增强，4d组反应最强，24d组有所减弱；24d组的SNC与对照组比较差异无统计学意义，但VTA与对照组比较，差异仍有统计学意义（P〈0，05）。结论 （1）脑震荡后大鼠出现近期空间学习记忆功能障碍；（2）脑震荡后多巴胺能神经元酪氨酸羟化酶表达增高。Objective To study the features of cognitive behavioral deficits and the change of dopaminergic neuron after brain concussion in rats. Methods An animal model of concussive brain injury in rats was duplicated with a metallic pendulum-striker concussive device. Rats subjected to brain concussion were divided into 6 groups（n = 12 in each group： the l, 2, 4, 8, 16, and 24 day groups postconcussive injury）. There were 12 normal rats in the control group. Learning and memory ability were evaluated by Morris water maze （MWM） method. The changes of dopaminergic neurons in substantia nigra pars compact （ SNC ） and ventral tegmental area （VTA） in midbrain were studied using immunohistochemistry method. Results The escape latencies were longer statistically in the treated groups than in the control group on days 1-3 post-concussion. Within the period of days 4-21, MWM test was not signifi- cantly different from the controls. Tyrosine hydroxylase （TH）-immunoreaction （TH-IR） increased significantly in the SNC and VTA on 1 day post-concussion. The most significant change occured in the 4-day group. The expression of TH-IR in SNC had a descending tendency in the 8-day and 16-day groups com- pared to the 4-day group, and recovered in the 24＋day group, but TH-IR in VTA still increased significantly compared to the control group. Conclusions The spatial learning and memory deficits of the rats are found in early period of post-brain concussion. The expression of TH-IR of dopaminergic neurons increases following brain concussion. We speculate that the increase in TH in earlier period may be caused by neuronal transient overexcitation following post brain concussion, and the increase in TH remained a period of time, which may reflect a compensatory response of dopaminergic neurons to up-regulate their synthesizing capacity in order to increase the efficiency of dopamine neurotransmission.

关 键 词：脑震荡 认知 多巴胺 大鼠 

分 类 号：R686[医药卫生—骨科学]