高压氧促进大鼠弥漫性轴突损伤后学习记忆功能恢复的实验研究

目的：研究高压氧（HBO）治疗对弥漫性轴突舌鼠学习记忆功能的影响。方法：采用Marmarou介绍的落体打击装置制作弥漫性轴突损伤（DAI）大鼠模型，一组大鼠在致伤前进行Y型迷宫训练，另一组不预先训练，分别观察高压氧治疗对致伤大鼠迷宫空间辨别记忆及学习功能的影响，并用免疫组化的方法观察海马区ChAT阳性纤维表达变化。结果：无论经是否进行Y迷宫训练，损伤大鼠条件反射数（conditioned reflex number,CN)明显高于空白对照组（blank)大鼠（P＜0．05）；预先Y迷宫训练后的大鼠造成DAI损伤后，HBO组与对照组（control)相比CN次数无明显差别；未预先训练组中HBO治疗大鼠CN次数明显少于对照组（P＜0．05）；HBO治疗后损伤大鼠海马区ChAT阳性纤维表达显著增强。结论：弥漫性脑损伤后大鼠的学习能力和记忆力均下降，而高压氧治疗能改善脑损伤大鼠学习障碍，但对记忆障碍的影响不大；高压氧治疗能增强海马区神经元活性，抑制外伤后ACh能神经元发生的退行性变，这可能是高压氧改善脑损伤大鼠学习记忆障碍的机制之一。

Effect of hyperbaric oxygen improving learning and memory for rats with diffuse axonal injury

AIM To investigate the effects of hyperbaric oxy- gen (HBO ) treatment on Sprague- Dawley rats'ability of learning and memory after diffuse axonal injury (DAI) . METHODS The head- injured anim al models were produced by an weight- droptdevice designed by Marmarou.Rats were randomly divided into4 groups.Rats in group A were trained in Y- maze for7d before impact injury and those in group B were not trained before injury. The conditioned reflex num - ber (CN ) after HBO therapy in two groups was measured with the establishment of injured and blank controls,The samples of each rat's brain in group C and group D were tak- en to do the choline- acetyltransferase(Ch AT) immunohis- tochemical staining and were examined under light micro- scope.RESUL TS CN of DAI rats was greater than that of blank control group;the difference of CN was not statistical- ly significant between HBO group and control group in group A;while in group B,CN of HBO group was significantly less than that of injured group;the Ch AT- positive fibers in hip- pocampus almost vanished after DAI and the positive fiber were markedly increased after HBO.CONCL USION The a- bility of learning and memory of rats mightbe decreased after DAI. HBO could improve learning ability of the injured rats. HBO also could activate neurons in hippocampus and inhibit regression of cholinergic neurons,which may be one of the mechanisms of improvement of the learning ability of injuried rats by HBO.