Effects of sub-anesthetic doses of ketamine on rats' spatial and non-spatial recognition memory

There are experimental evidences indicating that the non-competitive N-methyl-D-aspartate (NMDA) receptor antagonist ketamine impairs cognition and produces a series of schizophrenia-like symptoms in rodents (hyperactivity, stereotypies and ataxia). The present study was designed to investigate the effects of ketamine on rats' non-spatial and spatial recognition memory. For this purpose the object recognition and the object location task were selected. Pre- or post-training systemic administration of ketamine (0.3, 1 and 3 mg/kg; i.p.) in a dose-dependent manner disrupted animals' performance in both these recognition memory paradigms, suggesting that this compound affected pre- and post-training memory components. The current results indicate that the non-competitive NMDA antagonist ketamine may modulate either spatial or non-spatial recognition memory.