GPR88 and psychiatric disorder: Obvious low sensitivity to haloperidol was observed in GPR-88 KO mice, with haloperidol being less effective in blocking climbing in GPR-88 KO mice than in WT mice; prepulse inhibition of startle response (PPI) is disrupted in GPR-88 KO mice (deficits in sensorimotor gating is a symptom of several psychiatric disorders and is exhibited by schizophrenic patients).