Abstract: Objective To explore the correlation between signs similar to schizophrenia in mice after ketamine administration and the expressions of NRG1 and ErbB4 mRNA in order to explain the possible pathogenesis of schizophrenia.Methods Fifty KM mice were randomly divided into 5 groups which were administered in-traperitoneally with saline,clozapine and different dosages ketamine.The ketamine groups were administered intraperitoneally with low dosage(25 mg/kg),middle dosage(50 mg/kg) and high dosage(100 mg/kg) one time every day for 7 days.After administration of 100 mg/kg ketamine for 7 days,the clozapine group was intro-gastrically administered 20 mg/kg with clozapine one time every day for 7 days.The pathological changes of hippocampus neurons were observed by HE stain.The expressions of the NRG1 and ErbB4 mRNA in hip-pocampus were detected by reverse transcriptase polymerase chain reaction(RT-PCR).Results In the group with high dosage of ketamine,the levels of NRG1 and ErbB4 mRNA were significantly lower than that of the group with saline.Conclusion Ketamine may induce signs similar to schizophrenia in KM mice.The mechanism may be involved in the reduction of NRG1 and ErbB4 mRNA expression.

Key words: forensic psychiatry, schizophrenia, ketamine, NRG1, ErbB4, mice