新型合成毒品4-甲基乙卡西酮对大鼠空间学习与记忆能力的远期影响

THE LONG- TERM EFFECTS OF SYNTHETIC CATHINONE 4- METHYLETHCATHINONE ON SPATIAL LEARNING AND MEMORY FUNCTIONIN IN RATS

目的:探讨卡西酮类新型合成毒品4-甲基乙卡西酮(4-MEC)的慢性使用对大鼠空间学习记忆能力的远期影响。方法:将50只♂SD大鼠随机分成4-MEC给药组(3 mg·kg-1、10 mg·kg-1和30 mg·kg-1)、甲基苯丙胺阳性对照组(3 mg·kg-1)和生理盐水对照组,每组10只,连续一周腹腔注射给药后进入为期两周的戒断。用Morris水迷宫实验比较各组在戒断2周后的空间学习与记忆能力、以及同等剂量药物再暴露后的空间记忆能力。结果:连续注射4-MEC的各组大鼠经过2周戒断后,在连续5 d的逃生习得训练过程中,逃生潜伏期与生理盐水对照组之间均无显著性差异。然而,与慢性生理盐水对照组接受4-MEC(10 mg·kg-1)注射后的空间记忆功能的指标相比,4-MEC戒断的大鼠再次给予4-MEC后,目标象限内滞留时间比、目标象限内移动距离比、虚拟平台穿越次数等反映空间位置记忆能力的指标发生明显的降低。结论:与没有4-MEC使用经验的动物相比,具有慢性使用经验的大鼠在长期戒断后,药物再暴露可造成空间记忆能力的显著下降。该结果揭示慢性卡西酮类毒品的使用对认知功能具有远期的损害作用。

Objective： To investigate the long- term effects of synthetic cathinones 4-Methylethcathinone（ 4- MEC） on the spatial learning and memory in rats.Methods： Rats received 4-MEC（ 3 mg·kg- 1,10 mg·kg- 1and 30 mg·kg- 1,respectively）,methamphetamine（ 3 mg·kg- 1） or saline（ 1 mL ·kg- 1） by intraperitoneal injection for 7 days. Two weeks after withdrawal,the performance on spatial learning and memory of all groups were accessed by Morris water maze. Then thirty- five minuses after re- exposure to respective drugs,the spatial memory was tested again.Results： There wasno difference on escape latency between all drug- withdrawn groups and chronic saline group during acquisition training. However, after re- exposing to 4- MEC, drug- withdrawn groups showed significantly lower scores on proportion of distance / time in target quadrant,and smaller number of platform crossings compared to chronic saline group,which was treated by single 4- MEC.Conclusions：Comparing with drug no- experienced group,re- exposure to 4- MEC caused robust impairment on theperformance of spatial memory in drug- experienced rats. The results imply the long- term and harmful effects of synthetic cathinones on cognitive function.