小剂量纳洛酮与氯胺酮合用对小鼠学习记忆的影响

Effects of Combination of Small-dose Naloxone and Ketamine on the Learning Memory of Mice

目的:观察小剂量纳洛酮与氯胺酮合用对小鼠学习记忆的影响。方法:将小鼠分为5组(n=10):生理盐水组(NS组)及纳洛酮1、10、100、1000ng·kg-1组(NL1、NL2、NL3、NL4组),各组皮下注射相应药物,3min后腹腔注射氯胺酮20mg·kg-1,随后分别进行跳台、避暗及Y迷宫实验,以不同时间测定的潜伏期、错误次数、一次性正确次数作为评估小鼠学习记忆能力的指标。结果:与NS组比较,跳台实验中纳洛酮各组小鼠的跳台潜伏期缩短(P<0.05),避暗实验中NL1、NL2、NL3组的潜伏期缩短(P<0.05),NL1、NL3组错误次数增加(P<0.05),Y迷宫实验中各组小鼠正确次数比较无统计学意义(P>0.05)。结论:在本实验条件下,小剂量纳洛酮与氯胺酮合用可增强小鼠在跳台、避暗实验中的遗忘作用,但对Y迷宫实验中学习记忆的能力无明显影响。

OBJECTIVE： To observe the effects of combination of small-dose naloxone （NL） and ketamine（KT） on the Iearning memory of mice. METHODS： Fifty mice were randomly divided into five groups, i.e. normal saline group （NS） and naloxone group （NL1, NL2, NL3, NL4, received NL 1,10,100, 1 000 ng·kg^-1, respectively）. Mice in each group were injected with relevant injection subcutaneously, 3 min later injected with ketamine 20 mg·kg^-1 intraperitoneally. The learning memory of mice were evaluated by step-down test, step-through test and Y-electrical maze test with latency, the error times and correct times for one time recorded at different time points as indexes. RESULTS： As compared with NS group, NL group showed shortening of latency in step-down test （P〈0.05）; Shortening of latency in step-through test were showed in NL1, NL2, NL3 group and increase of error times in NL1, NL3 group （P〈0.05）. No statistical significance was noted in correct times of each group in Y-electrical maze test （P〉0.05）. CONCLUSION： The combination of small-dose NL and KT may enhance the impairment of learning memory of mice in step-down test and step-through test while have no significant impact on learning memory of mice in Y-electrical maze test.