THE AMPA RECEPTOR ANTAGONIST GYKI-52466 REVERSES THE ANTI-CATALEPTIC EFFECTS OF THE COMPETITIVE NMDA RECEPTOR ANTAGONIST CGP-37849

The effects of the AMPA receptor antagonist GYKI 52466 ophenyl)-4-meth yl-7,8-methylenedioxy-5H-2,3-benzo- diazepine HCl) on haloperidol-indu ced catalepsy were tested in drug-naive rats and in rats pretreated wi th the competitive NMDA receptor antagonist CGP 37849 (DL-(E)-2-amino- 4-methyl-5-phosphono-3-pentenoic acid). CGP 37849 (4 mg/kg i.p.) given alone significantly reversed haloperidol-induced catalepsy (0.5 mg/kg i.p.) while GYKI 52466 (4.8 mg/kg i.p.) given alone was without effec t. Administration of GYKI 52466 to rats pretreated with CGP 37849 abol ished the anticataleptic effects of the competitive NMDA receptor anta gonist seen following single administration. Thus the AMPA receptor an tagonist prevents behavioural effects induced by a NMDA receptor antag onist in this behavioural model.