ADENOSINE A(2A) RECEPTORS IN THE NUCLEUS-ACCUMBENS MODULATE PREPULSE INHIBITION OF THE STARTLE RESPONSE

Prepulse inhibition (PPI) of the acoustic startle response (ASR) was d isrupted by systemic administration of apomorphine (APO) (2 mg/kg, i.p .). Microinfusion of the selective adenosine A(2a)-receptor agonist CG S21680 (0.05 mu g in 1.0 mu l per side) into the nucleus accumbens (NA c), had no significant effect in animals with systemic vehicle pretrea tment, but significantly reversed the disruption of PPI in rats pretre ated with APO. Adenosine is, therefore, involved in the control of PPI through its actions on A(2a) receptors in the NAc. APO-induced disrup tion of PPI is considered to represent an animal model useful for scre ening both typical and atypical antipsychotic agents. The present resu lts add further support to the view that A(2a)-receptor agonists may b e potentially useful antipsychotic agents.