MK-801 produces antianxiety effect in elevated plus-maze in mice

The antianxiety effect of the non-competitive NMDA receptor antagonist, MK-801, was investigated in the present study in the elevated plus-maze paradigm in mice. During a 5-min session of the test, the number of entries the animal made in open/and closed arm, preference of the animal for first entry, and average time each animal spent in open and closed arm were noted as parameters for anxiety-related movements. The effect of MK-801 was further explored by studying its interaction with the specific anxiolytic agent, diazepam; the anxiogenic beta carboline agent, FG 7142; and the central benzodiazepine receptor antagonist, flumazenil (RO 15-1788). MK-801 produced anxiolytic effects at all the doses investigated. It increased the preference of the animal for open arm in a dose-dependent manner and the effect was potentiated by diazepam. Both FG 7142 and flumazenil reversed the effects of MK-801 when these agents were concomitantly administered with MK-801. The study revealed the anxiolytic effect of MK-801, a non-competitive antagonist of NMDA-receptor, and also an interaction of the NMDA-receptor and GABA/BZ-receptor complex in anxiety-related behaviour in mice.