[Pain sensitivity changes in schizophrenic patients and animal models--Part II]

Diminished pain sensitivity in schizophrenic patients has been reported for more than 50 years, however little is known about the substrate and the basic mechanisms underlying altered pain sensitivity in this disease, therefore, relevant animal models are of decisive importance in the study of psychiatric diseases. The authors report a review consisting of two parts focusing on pain sensitivity changes in patients and in different animal models which proved the eligibility as schizophrenia models and pain sensitivities have also been determined. The second part of this article analyzed the results regarding knock out mice as schizophrenia models. These data proved that several genes have significant role in the pathomechanism of schizophrenia; therefore deficiency in one gene does not produce animals showing all signs of this disease. As regards the pain sensitivity changes, only a few data are available with controversial results. Data originated from complex chronic animal models indicate that they might be more adequate methods for studying the mechanisms of schizophrenia including the pain-sensitivity changes.