ABSTRACT
Objective To compare the effect of extinction using different methods and the subsequent reinstatement of morphine-primed on morphine-induced conditioned place preference (CPP). Methods Mouse received morphine(10 mg/kg, sc) or saline (10 mg/kg, sc) injections alternately for 8 days to establish CPP. Different methods were used for extinction. Program 1, withdrawal group. Extinction sessions were conducted 21 days after the CPP test at 7 days interval; Program 2, extinction test group. Extinction sessions were carried out once a day from the second day after the CPP test; Program 3, extinction training group. Extinction sessions began one day after the CPP test. Mice were treated alternately two trials daily, in compartments where they received saline instead of morphine. A test for reinstatement was performed on the 2nd or 7th day after all groups completed extinction by 5 mg/kg morphine-primed. Results Morphine injections induce strong CPP. In withdrawal group, CPP extinguished on the 35th day and maintained for at least 28 days. Six trials extinction tests and 4 trials extinction training caused morphine induced CPP extinction. The three programs mentioned above were all primed by 5mg/kg morphine. Conclusion Morphine induced mouse CPP model can maintain at least 28 days, both extinction test and training can accelerate the extinction of CPP, and reinstatement by 5 mg/kg morphine.
ABSTRACT
The surgical nutrition puts emphasis on the regulation of postoperative patients recently.The artical reviewed the effects of recombinant human growth hormone on metabolism, defence and wound healing of postoperative patients.