The effect of acute administration of risperidone on local cerebral glucose utilization in the rat

Risperidone (R 64 766, 3-[2-[4-(6-fluoro-1,2-benzisoxazol-3-yl)-1-pyperidinyl]ethyl )-6,7,8,9-tetrahydro-2-methyl-4H-pyrido[1,2-a]pyrimidin-4-one) has superior effects in treating negative symptoms of schizophrenia and causes less extrapyramidal side effects than traditional antipsychotics. In this study, we employed the [14C]2-deoxy-D-glucose method to map local cerebral metabolic activity of rats acutely administrated i.p. with 0.0, 0.1, 0.5, 1.0 and 2.0 mg kg(-1) risperidone. Risperidone in the highest dose produced a reduction of glucose utilization in 11 of the 38 regions examined. The results showed that the regions with metabolic change are somewhat different from those results studied with microdialysis and the Fos immunohistochemistry. Among the nuclei with metabolic changes, the hippocampus and the mediodorsal nucleus of the thalamus may be related to the therapeutic action of risperidone and require further study.