REVERSAL OF A DIZOCILPINE-INDUCED DISRUPTION OF PREPULSE INHIBITION OF AN ACOUSTIC STARTLE RESPONSE BY THE 5-HT2 RECEPTOR ANTAGONIST KETANSERIN

Prepulse inhibition can be reliably disrupted by non-competitive NMDA receptor antagonists such as dizocilpine. In a recent study, we found that the potent D-2/5-HT2 receptor antagonist, risperidone, but not th e selective dopamine D-2 receptor antagonist, raclopride, could revers e this disruption. The present study was therefore designed to examine the effect of the 5-HT2 receptor antagonist, ketanserin, against a di zocilpine-induced disruption of prepulse inhibition, as well as the be havioural stereotypy produced by this drug. Ketanserin (2 mg/kg) rever sed the prepulse inhibition disruption produced by dizocilpine (0.15 m g/kg), as did the non-selective 5-HT1/5-HT2 receptor antagonist meterg oline (1 mg/kg). Both drugs also attenuated some components of the beh avioural stereotypy syndrome produced by dizocilpine (0.15 mg/kg). The present studies therefore suggest an interaction between 5-HT2 recept ors and glutamatergic systems. This may be important for the antipsych otic profile of drugs having antagonist activity at 5-HT2 receptors.