NGF预防大鼠额叶皮质损伤后基底前脑胆碱能神经元变性

Retrograde Degeneration of Cholinergic Neurons of Basal Forebrain Induced by Frontal Cortexes Injuries is Prevented by NGF in Rats

目的 为了观察神经生长因子(NGF)对大鼠额叶皮质损伤后基底前脑胆碱能神经元变性的预防效果。方法 24只SD大鼠,随机平均分为3组:①实验组(NGF),②对照组(等容量的生理盐水),③正常组(假手术)。用外科手术造成双侧额叶皮质局限性损伤。动物的学习、记忆机能及基底前脑含乙酰胆碱酯酶(AChE)活性神经元则分别用Y型迷宫和组织化学方法进行检测。结果 额叶皮质损伤4周后,动物的学习、记忆机能明显下降(P<0.01),基底前脑含AChE活性神经元明显减少(P<0.01)。NGF治疗可有效地防止额叶皮质损伤大鼠学习、记忆障碍的发生及基底前脑含AChE活性神经元的减少(P<0.05)。结论 NGF对双侧额叶皮质损伤大鼠的学习、记忆机能障碍及基底前脑胆碱能神经元变性有预防效果。

Objective To observe the preventive effects of NGF on the retrograde degeneration in cholinergic neurons of basal forebrain in rats with frontal cortexes injuries. Methods Twenty-four SD rats were randomly divided equally into 3 groups.①experiment group(NGF, ip),② control group (equivolume 0.9% salt solution, ip), ③ normal group(sham operation).The bilateral frontal cortexes were injured by surgical operation. The animals were placed on an electrified grid in a Y-maze and learned to run into the light arm (safe area) 4 weeks after the frontal cortexes injuries. The criterion of learning or memory retrieval was met after the animals had correctly made 10 of 10 consecutive choices. The histochemical method to demonstrate AChE-containing neurons in the basal forebrain is based on the direct coloring procedure of Karnovsky and Roots. Results The significant increase in the number of trials needed to meet the criterion in the rats 4 weeks following the damage to the frontal cortexes was observed as compared with that in the normal animals (P<0.01). The number of AChE-rich neuron of the basal forebrain in the rats with the frontal cortexes injuries significantly decreased as compared to that in the normal animals. The numbers of trials needed to meet the criterion and of AChE -rich neurons of the basal forebrain in the animals of the experiment group were not significantly different from those in the normal animals. Conclusion NGF treatment could not only prevented from occurrence of learning or memory disturbance, but also from retrograde degeneration of the AChE-rich neurons of the basal forebrain in the rats with bilateral frontal cortexes injuries.