The main purpose of this study was to examine the effects of intraventricular injections of glutamate and aspartate on the walking gait of rendered ataxic by the administration of 3-acetyl pyridine. Both amino acids significantly improved the walking gait of these animals. The effects of other substances known to have a stimulatory influence on locomotor activity in rats were also investigated. Amphetamine, apomorphine and thyrotropin releasing hormone (TRH) had no effect on the ataxic gait of 3-AP treated animals. Substance P significantly improved the gait of ataxic animals, but to a lesser extent than that seen with glutamate and aspartate.