东莨菪碱对吗啡诱发条件位置性偏爱重现大鼠杏仁核p-CREB及c-Fos表达的影响

Effects of scopolamine on expression of p-CREB and c-Fos in amygdala nucleus in rats with recurrence of conditioned place preference induced by morphine

目的:探讨东莨菪碱对吗啡诱发条件位置性偏爱(conditioned place preference,CPP)重现大鼠杏仁核(amygdala nucleus,Amy)cAMP反应元件结合蛋白(phospho-cAMP response element binding protein,p-CREB)和c-Fos表达的变化。方法:以剂量递增法建立大鼠CPP模型,生理盐水替代吗啡训练大鼠,使形成的CPP逐渐消退,小剂量吗啡激活已消退的CPP。采用免疫组化技术测定不同剂量东莨菪碱对吗啡诱发CPP重现时大鼠杏仁核p-CREB和c-Fos的变化。结果:东莨菪碱可抑制吗啡点燃诱发大鼠CPP重现行为;并可减少吗啡诱发的CPP重现时大鼠杏仁核p-CREB和c-Fos的表达。结论:东莨菪碱对小剂量吗啡诱发吗啡依赖大鼠CPP重现行为的抑制作用可能与其抑制大鼠杏仁核p-CREB和c-Fos蛋白表达有关。

AIM： To dectect the effects of scopolamine on expression of phospho-cAMP response element binding protein （p-CREB） and c-Fos in amygdala nucleus （Amy） in rats with recurrence of conditioned place preference（CPP） induced by morphine. METHODS： Morphine was administered by subcutaneous injection at gradually increasing dose（from 10 mg/kg to 60 mg/kg）for 6 days to establish CPP model. From d 7, the rats were administered saline instead of morphine for 10 days to induce CPP extinction. The rats were given a single priming injection of morphine （4 mg/kg） to reinstate the CPP model, some rats were treated by i.p. scopolamine （1, 2, 3 mg/kg） prior to priminging injection of morphine. The expression of p- CREB and c-Fos in Amy were assayed by immunohistochemistry in the phase of reoccurrence of CPP. RESULTS： After priming injection of morphine 4 mg/kg, the time spent on the drug paired side was significantly reduced because of the treatment with scopolamine, compared with that in the morphine group（ P 〈 0.05）. Compared with the morphine group, scopolamine decreased the expression of p-CREB and c-Fos of Amy in rats （ P 〈 0.05）. CONCLUSION： The effects of scopolamine inhibiting morphine CPP reccurrence were probably related to its inhibitory effect on p-CREB and c-Fos expression of Amy in rat.