额叶皮质损伤对大鼠基底前脑胆碱能神经元的影响

本实验探讨了前额叶皮质局限性损伤对大鼠学习、记忆功能及基底前脑胆碱能神经元的影响。用外科手术造成大鼠一侧前额叶皮质局限性损伤后不同时间、用Ｙ型迷宫检测学习、记忆功能、用组织化学技术检测基底前脑含乙酰胆碱酸酶（ＡChE)活性神经元。实验观察到前额叶皮质损伤后１周，动物学习，记忆功能有所障碍，损伤同侧的基底前脑胆碱能神经元有所减少，但均无统计学意义，损伤后２，３，４周，动物学习、记忆障碍明显，损伤同侧基底前脑胆碱能神经元明显减少（Ｐ＜0.05)，且两者变化相平行。结果表明单侧前额叶皮质局限性损伤不仅可引起动物学习、记忆功能障碍，且可引起同侧基底前脑胆碱能神经元丢失，且两者发展相平行，提示基底前脑胆碱能神经元逆行性变性在动物额叶皮质损伤引起的学习、记忆障碍中起作用。

Effects of frontal cortexes injuries on cholinergic neurons of basal forebrain in rats

The effects of the frontal cortexes injuries on learning and memory of discrimination performance and the cholinergic neurons of the basal forebrain were observed in the rats. The unilateral frontal cortexes injuries were made by the surgical operation in the rats. The learning and memory ability of discrimination performance was determined in a Y maze at various time after the injuries. The histochemical method to demonstrate AChE containing neurons in the basal forebrain is based on the direct coloring procedure of Karnovsky and Roots. The significant increase in the number of trials needed to meet the criterion in the rats, which began the behavioral training 2,3 or 4 weeks following injuring the frontal cortexes, was observed as compared with that in the control animals ( P <0.01). The number of AChE rich neurons in the nucleus basalis magnocellularis (NBM), the medial septal nucleus (MS) and the vertical nucleus and the horizontal nucleus of the diagonal band (VDB and HDB) ipsilateral to the injury significantly decreased as compared to that in these nuclei contralateral to the injury in 2, 3, or 4 weeks after injuring the frontal cortexes in the rats ( P < 0.05). No significant changes in learning or memory activity and the number of the AChE rich neurons in the basal forebrain were detected 1 week after injuring the frontal cortexes ( P >0.05). The unilateral frontal cortexes injuries not only could induce disturbance of learning or memory activity of the visual discrimination, but also cause decrease in the AChE rich neurons of the basal forebrain in the rats. Both changes progressed identically. It is suggested that maybe the retrograde degeneration of cholinergic neurons in the basal forebrain plays a role in the disturbance of the learning and memory activity in the rats with frontal cortexes injuries.