An attempt of behavioral analysis of model mice for schizophrenia

Abstract

An approach of behavioral pharmacologic methods using animal models greatly contributed to the progress of understanding of symptoms of schizophrenia, evaluation of animal models of schizophrenia and development of therapeutic agents. Although genetically modified mice provide indispensable information for understanding the functions of target genes, studies on behavioral alteration of genetically modified mice showed inconsistent results. In this study, we used congenic dopamine D1 and D2 receptor knockout (D1R KO, D2R KO) mice and compared them simultaneously under the same conditions. We monitored their motor activity in their home cages continuously for five days as normal spontaneous activity, in which the effects of external factors are negligible. For better understanding of characteristics of motor activity, we measured the intensity of activity and the duration and number of active and inactive bouts by examining the data of the motor activity in the home cage. In addition we measured the volume of food and water intake while monitoring the motor activity. In monitoring spontaneous motor activities, D1R and D2R KO mice showed higher and lower 24 h activities, respectively, than wild type mice. We consider this novel analytical methods can be applied to analysis of behavioral alteration of animal models of schizophrenia.