Phencyclidine (PCP)-induced deficits of prepulse inhibition in monkeys

Prepulse inhibition (PPI) of the acoustic startle reflex is a measure of se nsorimotor gating which occurs in both rodents and humans. PPI is deficient in severe neuropsychiatric disorders such as schizophrenia. We investigate d PPI in 10 adult monkeys (Cebus apella). Stimuli were 115 dB white noise s tartle pulses, either alone or preceded by 120 ms with a prepulse of either 8 or 16 dB above the 70 dB background noise. Experiments included a pretre atment baseline session and a session following treatment with either phenc yclidine (PCP, 0.12 mg/kg, i.m.) or saline. Comparison of peak amplitudes i ndicated a significant intensity-dependent decrease in startle response tha t was similar to that observed in humans under similar experimental conditi ons. PCP treatment significantly disrupted PPI, but did not reduce response s to startle pulses alone. These results provide the first demonstration of PPI in monkeys. The ability of PCP to induce schizophrenia-like deficits i n PPI suggests that PPI in nonhuman primates may provide an important anima l model for the development of novel anti-schizophrenia medications. NeuroR eport 12:117-120 (C) 2001 Lippincott Williams & Wilkins.