Anxiolytic-like and antinociceptive effects of MK-801 accompanied by sedation and ataxia in primates.

Anxiolytic-like and antinociceptive activities of the noncompetitive NMDA receptor antagonist MK-801 (dizocilpine) were compared with sedative and ataxic side effects in primates. Administration of MK-801 (0.1 mg/kg) caused taming in cynomolgus monkeys and increased tail withdrawal latencies in squirrel monkeys; both effects were accompanied by sedation and ataxia. These findings are discussed in relation to the possible therapeutic uses of NMDA antagonists and differences in the behavioural effects of such compounds in primate and rodent species.