Subchronic haloperidol and sulpiride treatment induces region-specific changes in tissue levels of putative amino acid transmitters in rat brain.

The effect of 10 days treatment with haloperidol (0.5 or 2 mg/kg/day) or sulpiride (10 or 100 mg/kg/day) on regional brain tissue levels of GABA, glutamate, aspartate and glutamine was studied in the rat. The GABA levels were increased in the nucleus (nuc.) accumbens and striatum by haloperidol, but not by sulpiride. The glutamate and glutamine levels were increased in the nuc. accumbens by both drugs. The aspartate levels were increased in the nuc. accumbens by sulpiride. Tissue levels of all 4 amino acids studied remained unchanged in the substantia nigra following the drug treatment. These results indicate that dopaminergic activity has a region-specific influence on the utilization of aspartate, glutamate and GABA in rat brain.