Antipsychotics alter the protein expression levels of β-catenin and GSK-3 in the rat medial prefrontal cortex and striatum

Background: It has been demonstrated that schizophrenics have altered levels and/or phosphorylation states of several Wnt related proteins in the brain, including beta-catenin and GSK-3, and may represent susceptibility loci for schizophrenia. The current study was conducted to assess the effects of antipsychotics on beta-catenin and glycogen synthase kinase-3. Methods: Western blotting and immunocytochemistry were employed to investigate the effects of antipsychotics on beta-catenin and glycogen synthase kinase-3 following acute, subchronic and chronic drug administration. Specificity of the response was tested using additional drugs such as fluoxetine, amphetamine and valproic acid. Results. Significant increases in the levels of beta-catenin and glycogen synthase kinase-3 total protein were identified following administration of clozapine, haloperidol or risperidone. The phosphorylation state of GSK-3 was also increased but phosphorylated beta-catenin levels were unaffected. Other drug compounds, with the exception of raclopride, bad no effect on either GSK-3 or beta-catenin protein levels or distribution. Conclusions: Targeting of beta-catenin and GSK-3 is a common feature of antipsychotics regardless of class and appears to be mediated by D-2 dopamine receptors. Therefore changes in beta-catenin and GSK-3 may represent one of the mechanisms through which antipsychotics are able to exert behavioral changes.