氟西汀对条件恐惧消退大鼠边缘下皮质Erk1/2磷酸化的影响  

Effect of Fluoxetine to phosphorylation of ErK1/2 in rat infra-limbic cortex following conditioned fear extinction

作　　者：赵红念[1] 蒋丽珠[2] 李云[1] 

机构地区：[1]大理学院附属医学院神经内科,云南大理671000 [2]大理学院临床医学院神经精神教研室,云南大理671000

出　　处：《中国现代医学杂志》2012年第20期13-17,共5页China Journal of Modern Medicine

基　　金：国家自然科学基金(No:30860089)

摘　　要：目的研究氟西汀对条件恐惧消退大鼠内侧前额叶皮质边缘下区p-Erk1/2表达的影响。方法 16只成年雄性大鼠随机分成单纯条件恐惧消退组和氟西汀干预条件恐惧消退组,实验动物采用单调声配对电击大鼠足底造成条件恐惧刺激模型,氟西汀干预组灌胃给予氟西汀14 d,对照组灌胃给予生理盐水。后行消退训练并检测动物的静止不动时间(freezing time);处死动物,冷冻切片行内侧前额叶皮质边缘下区p-Erk1/2的免疫组织化学染色。结果行为学结果显示氟西汀干预组大鼠条件恐惧消退训练后静止不动时间百分比显著低于单纯条件恐惧消退组;p-Erk1/2的免疫组织化学染色显示氟西汀干预组大鼠条件恐惧消退训练后内侧前额叶皮质边缘下区p-Erk1/2表达明显增加,p-Erk1/2阳性细胞显著增多。结论氟西汀促进大鼠恐惧记忆的消退,其作用机制可能为通过促进大鼠内侧前额叶皮质边缘下区Erk1/2活化而发挥作用。[Objective] To investigate the effect of Fluoxetine to phosphorylation of extracellular signal regulated kinase 1/2 （p-ErK1/2） in rats＇ infra-limbic cortex following conditioned fear extinction. [Methods] 16 rats were divided randomly into two groups, fear extinction group with Fluoxetine pretreated and fear extinction control group with normal saline pretreated. All animals were given monotone matching foot shock and made of conditioned fear stimulus model, rats in Fluoxetine pretreated group were given Fluoxetine （10 mg/kg· d） intragastrically for 14 days, and rats in normal saline pretreated control group were given normal saline in- tragastrically for 14 days. Then all rats were given extinction train, rats were given only monotone stimulus and the freezing time during after each monotone stimulus were inspected. After extinction train, rats were sacrificed and immunohistochemistry for p-Erkl/2 was detected. [Results] Behavioral assessment showed that the percent of freezing time in Fluoxetine pretreated group was significantly lower than that in normal saline pretreated control group （P 〈0.05）. Compared to normal saline pretreated control group, the expression of p- Erkl/2 and p-Erkl/2 positive cells in infra-limbic cortex of rats in Fluoxetine pretreated group were significantly increased （P〈0.05）. [Conclusion] The mechanism of Fluoxetine to promote fear extinction in rats may be through activating Erkl/2 in infra-limbic cortex.

关 键 词：氟西汀 条件恐惧消退 边缘下皮质 P-ERK1/2 

分 类 号：R246.6[医药卫生—针灸推拿学]