条件恐惧记忆形成中大鼠海马CA1区钙调, 蛋白激酶Ⅱ和蛋白磷酸酶1蛋白表达及活性变化

Expression of Ca2+/calmodulin-dependent protein kinase Ⅱ and protein phosphatase 1 in the hippocampus CA1 area of rats during the formation of fear memory

摘要:

目的: 探讨大鼠恐惧记忆形成过程中海马CA1区钙调蛋白激酶Ⅱ(CAMKⅡ)和蛋白磷酸酶1(PP1)表达的变化.方法: 将大鼠随机分成电击组(n=9)和对照组(n=9),24 h后处死动物,提取海马CA1区蛋白,用anti-CAMKⅡ、anti-p-CAMKⅡ(T286)和anti-PP1、anti-PP1α(T320)抗体作蛋白印迹,检测电击对CAMKⅡ和PP1蛋白表达及活性的影响.结果: 电击组的大鼠在1 h和24 h海马CA1区CAMKⅡ蛋白表达较对照组增加了4.4±1.2倍,并且其286位的苏氨酸磷酸化的CAMKⅡ蛋白表达较对照组增加了3.3±0.8倍(P<0.05).电击组PP1蛋白表达较对照组增加了3.6±1.1倍,并且PP1α320位的苏氨酸磷酸化信号较对照组增加2.3±0.6倍(P<0.05).结论: 大鼠条件恐惧记忆形成过程中海马CA1区CAMKⅡ和PP1蛋白的表达增加,活性增强.CAMKⅡ和PP1介导的磷酸化信号参与了条件恐惧长时记忆的形成.

Abstract:

Objective: To investigate the expression and activity of Ca²⁺/calmodulin-dependent protein kinase Ⅱ(CAMKⅡ) and protein phosphatase 1(PP1) in the hippocampus CA1 area of rats with conditioned fear.Methods: Rats were randomely divided into two groups(n=9 each):conditioned fear model and control.24 hrs after rat model of conditioned fear was established,rats were sacrificed and expression of CAMKⅡ,phosphorylated CAMKⅡ(T286),PP1 and phosphorylated PP1α(T320) in the hippocampus CA1 area were detected by Western blot.Results: Compared with the control group,expression of CAMKⅡ increased by 4.4±1.2 times(P<0.05),phosphorylated CAMKⅡ(T286) increased by 3.3±0.8 times(P<0.05),expression of PP1 increased 3.6±1.1 times(P<0.05),and phosphorylated PP1α(T320) expression increased by 2.3±0.6 times(P<0.05) in the model group.Conclusions: The expression and activity of PP1 and CAMKⅡ increase significantly in the hippocampus CA1 area of rats with conditioned fear.PP1 and CAMKⅡ may play important roles in the formation of long-term memory of conditioned fear.