THE MODULATION OF SENSORIMOTOR GATING DEFICITS BY MESOLIMBIC CHOLECYSTOKININ

The effects of cholecystokinin (CCK) in an animal model of sensorimoto r-gating deficits with strong face, construct and predictive validity for schizophrenia were investigated. Prepulse inhibition (PPI) occurs when a weak acoustic lead stimulus inhibits the startle response to a loud startling stimulus. Infusions of sulfated CCK-8 in the posterior nucleus accumbens potentiated apomorphine-induced disruption of PPI bu t had no effect on baseline PPI or the amplitude of acoustic startle r eflex itself. The results provide evidence that mesolimibic CCK may pl ay a role in regulating sensorimotor gating deficits but contradict ea rlier notions that CCK agonists may have antipsychotic properties and upon which clinical trials of CCK agonists in schizophrenia were based . Rather, these results suggest that antagonists of CCK may display ne uroleptic-like actions on deficits in PPI and may hold greater promise as antipsychotics. (C) 1997 Elsevier Science Ireland Ltd.