ABSTRACT
Objective To establish models of different susceptibility of heroin-induced conditioned place preference (CPP) in rats and investigate the relation between novel environmental response and heroin-dependent susceptibility. Methods After an open-field test, 70 male Sprague-Dawley rats were classified into 2 groups according to the numerical value of heroin-induced CPP, each accounting for 30%. The correlation between open-field test and CPP was analyzed. Results CPP value was much higher than pre-test scores in the rats after exposure to heroin (P<0.01). Compared with the low-CPP group, the high-CPP group had much higher scores in open-field test (P<0.01). The deviation of resident time at natural preference side tested and pre-tested had positive correlation with open-field test (P<0.05). Conclusion Heroin-induced CPP model of different susceptibilities could be successfully established by chronic heroin exposure. The novel environmental response is a reliable predictor for its vulnerability to develop heroin dependence.