氯胺酮对幼年大鼠学习能力和海马细胞外信号调节激酶表达的影响

目的:研究不同剂量氯胺酮对幼年大鼠学习记忆能力影响,并观察其对海马神经元细胞外信号调节激酶表达的影响。方法:48只21日龄SD大鼠随机分为6组,C组(正常对照组),T组(训练组),K0组(0.9%Nacl组),K1组(25mg/kg氯胺酮组),K2组(50mg/kg氯胺酮组),K3组(100mg/kg氯胺酮组),每组8只。K1,K2,K3组大鼠分别予以25mg/kg,50mg/kg,100mg/kg氯胺酮腹腔注射(ip),N组予等量生理盐水腹腔注射,在注射后24h用Y型迷宫测试各组大鼠的空间搜索和学习能力,训练组只接受Y迷宫测试。所有动物训练后即刻取大鼠海马行免疫组化染色,观察ERK1,ERK2和p-ERK1/2表达情况。结果:K2、K3组大鼠的训练次数和总反应时间与T组和K0组比较有显著性差异(P<0.05);免疫组化显示K3组大鼠海马ERK1,ERK2和p-ERK1/2的表达与T组和K0组相比有显著性差异(P<0.05)。结论:麻醉剂量和大剂量氯胺酮可损害幼年大鼠的空间学习能力,而这个损害与海马ERK信号转导通路受到抑制有关。

Effect of ketamine on ERK expression in hippocampal neural cell and learning ability of young rats

Objective:To study the effects of ketamine on ERK expression in hippocampal neural cell and the learning ablility of young rats of ketamine.Methods:forty eight Sprague-Dawley rats of 21 days old were randomly divided into 6 groups,normal control group(C group),training group(T group),normal saline group(K0 group),ketamine group(25mg/kg K1group,50mg/kg K2group,100mg/kg K3group).Ketamine group rats were intraperitoneally(i.p.)anesthetized with ketamine of corresponding dose.K0 group rats were received equal volume normal saline.The Y-maze was used to test the ability of learning and spatial localization on rats in 24h after i.p..The training group only received light-electricity integrated training.At the end of training,all rats were killed and the ERK1,ERK2 and p-ERK1/2 was tested by using immunhistochemistry.Results:The learning times and total reaction time(TRT)of K2,K3 groups have significant differences compared with T group and K0 group(P<0.05).Immunohistochemical staining showed that the expression of ERK1,ERK2 and p-ERK1/2 in hippocampal neural cell of K3 groups significantly decreased compared with T group and K0 group(P<0.05).Conclusion:administration of ketamine may impair learning ability of 21 days old rats,especially in anesthetized dose and bigger dose.and ERK signal transduction pathway may be involved in the impairment by ketamine.