Abstract: Objective To investigate whether heroin can directly induce apoptosis in primary cultured cortical neurons of rat′s brain.Methods Cultured primary neurons cultures were obtained from cerebral cortex of embryo rats.After 7 days,the cells were incubated with different concentrations of heroin(purity～80%) for 24 hours.The neuronal survival was assessed by cell viability counting with fluorescent diacetate(FDA) staining.The morphological and biochemical changes were observed with Hoechst 33258 fluorescent staining and then analyzed by agarose gel electrophoresis,respectively.Results After treatment with different concentrations of heroin,the neurons showed a decreased survival rate in a dose dependent manner,and there was a significant difference in the survival rate between the heroin group and the control group(P<0.05).When exposed to different concentrations of heroin,neurons exhibited the morphological and biochemical features of apoptosis,including cell shrinkage,neurite degeneration,network disappearance,condensation and aggregation of nuclear chromatin,and the formation of DNA ladders.With the increase of heroin concentration of rat′s brain more apoptotic bodies were seen.Conclusion Heroin can directly induce apoptosis in primary cultured cortical neurons in rat′s brain.

Key words: heroin, cortical neuron, apoptosis