Alteration of Cytokines Levels in the Striatum of Rats: Possible Participation in Vacuous Chewing Movements Induced by Antipsycotics

Antipsychotic drugs have been used in the treatment of schizophrenia and their long-term use can cause movement disorders, such as tardive dyskinesia (TD) in humans mainly typical ones such as haloperidol. Neuroinflammation has been implicated to the use of antipsychotics besides its participation in TD remains unclear. Thus, the aim of this study was to investigate the relation of cytokines with vacuous chewing movements (VCMs) in rats comparing typical and atypical antipsychotics. Rats were treated with haloperidol or risperidone for 28 days. On day 29, rats were subjected to behavioral analysis (quantification of crossing and rearing numbers and VCMs) with subsequent measurement of cytokines levels in the striatum. Haloperidol, but not risperidone treatment significantly decreased the number of crossing and rearing and increased the VCMs when compared with control group. Both antipsychotics were able to increase the levels of pro-inflammatory cytokines (IL-1β, IL-6, TNF-α and IFN-γ) and decrease the anti-inflammatory cytokine (IL-10) in striatum of rats. However, IL-1β and IFN-γ levels were higher in animals treated with haloperidol than risperidone. Furthermore, positive correlations were observed between the cytokines (IL-1β and IFN-γ) and VCM numbers. Thus, the results suggest a role of inflammatory markers in the development of movement disorders, especially IL-1β and IFN-γ.