INTRAACCUMBENS INFUSION OF QUINPIROLE IMPAIRS SENSORIMOTOR GATING OF ACOUSTIC STARTLE IN RATS

Prepulse inhibition (PPI) of the startle reflex is reduced by systemic administration of dopamine (DA) agonists. Since PPI is impaired in pa tients with schizophrenia, the DA agonist-induced disruption of PPI in rats may be a useful model for studying the pathophysiology of impair ed sensorimotor gating in schizophrenia. In the present study, we repl icated the observation that PPI is disrupted by systemic administratio n of the D-2 agonist quinpirole, but not by the D-1 agonist SKF 38393. PPI caused by weak [1-5 dB(A)] or more intense [10 dB(A)] prepulses w as also disrupted by quinpirole infusion into the nucleus accumbens (N AC). The effects of intraaccumbens quinpirole on PPI were blocked by p retreatment with the D-2 antagonist haloperidol. These results support the notion that the reduction of PPI after systemic administration of DA agonists is mediated via stimulation of NAC D-2 receptors.