Comparison of effects of the different dosage MK-801 on recognition memory in rats

Abstract

Objective To observe the behavioral effects of acute administration of dizocilpine(MK-801) in rats, and to determine an appropriate doses of the drug to mimicking memory deficits of schizophrenia. Methods 192 rats were randomly divided into model groups and control group, and given different doses of MK-801 or saline.Locomotor activity, pre-pulse inhibition (PPI) test and novel object recognition test were studied respectively. Results The spontaneous activity increased in a dose-dependent manner after the treatment of MK-801.The total distances of locomotor activity in 0.3 mg/kg group((127.04±32.35)m) exhibited a significant difference compared with control group((35.34±12.81)m, P<0.05). MK-801 decreased PPI in dose-dependent manner(P<0.01). MK-801 0.1 mg/kg((103.45±68.04)%) and 0.3 mg/kg ((41.55±62.93)%) groups showed significant differences compared to control group((200.39±30.97)%) in PPI.The discrimination index of 0.03 mg/kg group((15.78±6.23)%) and 0.1 mg/kg group((22.42±3.85)%) were lower than that in control group((39.42±3.86)%, P<0.05). Conclusion It is necessary for select right doses for model different endophenotypes of schizophrenia by MK-801.0.03 mg/kg of MK-801 is a relatively appropriate dosage to cause recognition memory damage. Key words: Schizophrenia; Dizocilpine maleate; Recognition memory