Immediate Motor and Striatal Changes After Haloperidol

In rodents, early gene expression in the striatum changes immediately after administration of dopamine D₂ receptor blockers (e.g., haloperidol). To examine whether humans also would show immediate brain alterations, researchers gave intravenous haloperidol (5 mg per 70 kg) to seven healthy neuroleptic-naive men (mean age, 23). The men underwent structural and functional magnetic resonance imaging (MRI) before haloperidol administration; 1 to 2 hours afterwards; and 24 hours later, which corresponds to one half-life of haloperidol. At each time point, investigators examined striatal volume and striatal-thalamic-motor cortex pathways and quantified extrapyramidal symptoms (EPS) on functional MRI by using a computer-based technique as particip…