Abstract: Objective To observe the symptoms similar to schizophrenia in mice after ketamine single or continuous injection and to evaluate the feasibility of schizophrenia model injected with different dose of ketamine.Methods A total of 40 male mice were randomly divided into 4 groups,which were injected intraperitoneally with physiological saline(control group),25 mg/kg ketamine(low dose group),50 mg/kg ketamine(middle dose group),and 100 mg/kg ketamine(high dose group) qd for 7 days continuously.The behavior changes of mice were observed.Results Hyperactivity,stereotyped behavior and ataxia(P<0.01) were observed in high dose group after single injection.After continuous injection of ketamine for 7 days,the middle dose group showed hyperactivity,stereotyped behavior and ataxia(P<0.05),stereotyped behavior and ataxia were more significant in high dose group(P<0.01).Conclusion Ketamine can induce the symptoms similar to schizophrenia in mice after single or continuous injection.The symptoms induced by high dose ketamine will be more prominent and stable after continuous injection.

Key words: forensic psychiatry, schizophrenia, ketamine, neurobehavioral manifestations, mice