Effect of Riluzole on MK-801 and Amphetamine-Induced Hyperlocomotion

N-methyl-D aspartate (NMDA) antagonists, such as MK-801, and the dopamine indirect agonist amphetamine are pharmacological models used for the evaluation of putative new treatments for schizophrenia. Since the psychotomimetic effects of NMDA antagonists have recently been linked to their ability to increase glutamate release and since the glutamate release inhibitor riluzole prevented NMDA antagonist neurotoxicity, we evaluated the effect of riluzole on hyperlocomotion induced by MK-801 (0.25 mg/kg) and amphetamine (2.5 mg/kg). Mice pretreated with riluzole (3 mg/kg) did not influence baseline or MK-801-induced behavior, but 10 mg/kg produced moderate hypolocomotion alone and somewhat prolonged MK-801-induced hyperlocomotion. Pretreatment with riluzole 10 mg/kg, but not 3 mg/kg, had a moderately depressant effect both on spontaneous and amphetamine-induced locomotion. Taken together, these results suggest that riluzole would not be particularly effective as a treatment for schizophrenia and the neurotoxic and behavioral effect of NMDA antagonists do not clearly correlate.