中药回神颗粒对弥漫性轴索损伤大鼠学习记忆功能的影响

Effect of Chinese medicine Hulshen granule on cognitive outcome following diffuse axonal injury： experiment with rats

目的观察中药复方制剂回神颗粒对弥漫性轴索损伤（DAI）大鼠学习记忆功能的影响并探讨其机制。方法采用冲击加速度法用雌性Wistar大鼠复制DAI模型。20只模型大鼠随机均分为治疗组和损伤组，治疗组建模后24h开始连续14d给予回神颗粒灌胃，损伤组不治疗。以假手术大鼠10只为对照（假手术组）。伤后第14天开始连续5d以Morris水迷宫（MWM）试验检测各组大鼠定位航行试验的逃避潜伏期和空间搜索试验的目标象限逗留时间百分比及跨越原平台位置次数；第20天记录大鼠脑部穿通纤维到海马齿状回通路的长时程增强（LTP），结果以兴奋性突触后电位（EPSP）斜率与EPSP基线值比较的百分数表示。分别用HE染色和B淀粉样前体蛋白（β-APP）免疫组织化学染色检查伤后24h和14、20d大鼠脑组织病理学改变和B-APP的表达。结果损伤组大鼠MWM定位航行试验逃避潜伏期为（32．8±4．6）s，明显长于治疗组和假手术组[分别为（20．3±0．7）、（16．8±0．8）s，均P〈0．05]；目标象限逗留时间百分比为（36．4±3．2）％，跨越原平台位置次数为（4．5±0．6）次，均明显低于治疗组和假手术组[分别为（46．0±2．4）％、（46．9±2．1）％，（6．8±0．8）、（8．1±0．8）次，均P〈0．05]；LTP为（101．4±3．3）％，明显低于治疗组和假手术组[分别为（116．3±6．7）％、（117．9±2．8）％，均P〈0．05]。治疗组各项测试结果与假手术组之间差异均无统计学意义。损伤组与治疗组大鼠伤后24h均出现典型的DAI病理变化，14、20d均有所恢复。结论回神颗粒具有促进DAI大鼠学习记忆能力恢复的作用，这可能与海马区突触可塑性的改善有关。

Objective To investigate the influence of Chinese medicine Huishen granule （HG） containing ginseng, grassleaved sweetlag rhizome, pilose deer antler, etc, on learning and memory functions in diffuse axonal injury （DAI） and the mechanisms thereof. Methods Impact acceleration method was used to establish DAI Wistar rat models. Twenty model rats were randomly divided into 2 equal groups, the DAI ＋ HG group treated with gastric perfusion of HG 3 times a day since 24 h after the establishment of model for 14 days, and the DAI group without treatment. Ten rats underwent sham operation as controls. Fourteen days after the injury, Morris water maze （MWM） test was used to detect the rat＇s abilities of learning and memory for continuous 5 days. The changes of escape latency in acquisition of the task, the percentage of time spent in target quadrant, and the number of crossing the point of original platform in probe test were recorded. At day 20 after the-operation, the rats were subjected to long-term potentiation （LTP） recording in hippocampus to measure the percentage of slope and baseline of excitatory post-synaptic potential （EPSP）. Two rats from each group were killed 24 h, 14 d, and 20 d after the operation with their brains taken out, HE and immunohistochemical staining were employed to exam the brain lesion at 24 h, day 14 and 20 post-injury. Results The escape latency of the DAI group was （32.8 ± 4.6） s , significantly longer than those of the DAI ＋ HG and sham operation groups [ （ 20.3± 0.7 ） and （ 16.8 ± 0.8 ） s respectively, both P 〈 0. 05 ]. The target quadrant staying time percentage and number of platform location crossings of the DAI group were （36. 4 ± 3.2） % and 4.5 ± 0.6 respectively, both significantly less than those of the DAI ＋ HGandsham operation groups [（46.0±2.4）% and 6.8 ±0.8,and （46.9±2.1）% and 8.1±0.8 respectively, all P 〈 0.05 ]. The LTP level of the DAI group was （ 101.4± 3.3 ） % , significantly lower than those of the DAI ＋ HG and sham operation groups [ （ 116.3± 6.7） % and （ 117.9 ± 2.8 ） % respectively, both P 〈 0.05 ]. No significant differences in the parameters were found between the DAI ＋ HG and sham operation groups （ all P 〉 0.05 ）. Classical pathological changes of DAI occurred in the brains of the DAI and DAI ＋ HG groups at the time point of 24 h, and mitigated partly at the time points of day 14 and 20. Conclusion The learning and memory impairment of DAI was ameliorated significantly with the treatment of Chinese medicine HG, owing to the recuperation of synaptic plasticity in hippocampal area.