大鼠相关脑区p—CREB和c—Fos在吗啡点燃条件性位置偏爱条件下的变化

目的：研究磷酸化cAMP反应元件结合蛋白（phospho—cAMP response element binding protein，p-CREB）和c-Fos在吗啡点燃条件性位置偏爱激活大鼠海马、杏仁核表达的变化。方法：以剂量递增连续皮下（s．c．）注射吗啡6d建立吗啡诱导大鼠条件位置性偏爱（conditionedplacepreference，CPP）模型，第7天用生理盐水替代吗啡训练大鼠10d，使CPP消退，单次s．c．吗啡（4mg／kg）激发已消退的CPP。采用免疫组化技术测定吗啡激发CPP重现时大鼠海马、杏仁核p-CREB和c—Fos的变化。结果：吗啡可使大鼠产生CPP效应，吗啡4mg／kg可使已消失的CPP效应激活；吗啡诱发CPP激活时大鼠海马、杏仁核p-CREB和c—Fos的表达增加。结论：海马、杏仁核p-CREB和c—Fos蛋白的表达参与了吗啡点燃CPP重现。

Changes of p-CREB and c-Fos expression in brain regions of morphine-reactlvated conditioned place preference in rats

AIM: To investigate the changes of phospho-cAMP response element binding protein (p-CREB) and c-Fos in two brain regions of morphine-reactivated conditioned place preference (CPP) in rats. METHODS: Morphine was administered by subcutaneous injection at gradually increasing dose for 6 days to establish morphine CPP. From the 7th day, 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 to reactivate the morphine CPP. The p-CREB and c-Fos were assayed with immunohistochemistry method in the phase of recurrence of CPP rekindled by morphine. RESULTS: Increasing dose of morphine conditioning for 6 days resulted in acquisition of CPP and morphine (4 mg/kg) reactivated CPP following 10 days drug free period. Compared with saline control, morphine -reactivated CPP elevated the expression of p-CREB and c-Fos in hippocampus and amygdala in rats ( P < 0.05 ). CONCLUSION: p-CREB and c-Fos expression in hippocampus and amygdala may be involved in the mechanisms of recurrence of CPP.