Time course of prepulse inhibition disruption induced by dopamine agonists and NMDA antagonists: Effects of drug administration regimen

► Acute administration of amphetamine (5.0 mg/kg) or quinpirole (0.12 mg/kg) disrupted prepulse inhibition of acoustic startle response. ► Repeated administration of amphetamine (5.0 mg/kg) or quinpirole (0.12 mg/kg) lost its disruption. ► An escalating dosing regimen with amphetamine (1.0-5.0 mg/kg) produced a persistent disruption over time. ► Acute and repeated treatment of phencyclidine (0.50-2.0 mg/kg) or MK-801 (0.025-0.10 mg/kg) produced a stable and persistent disruption of PPI.