A sensitizing regimen of methamphetamine causes impairments in a novelty preference task of object recognition.

A neurotoxic regimen of methamphetamine impairs object recognition (OR) in rats. The present study investigated whether neurotoxicity is a necessary component of methamphetamine's effect on OR. Animals were exposed to a sensitizing regimen of methamphetamine, and were tested for OR one week, and locomotor behavior two weeks, later. Quantitative autoradiography was used to measure [(125)I]RTI-55 binding to forebrain dopaminergic and serotonergic transporters. Methamphetamine treatment produced significant OR impairments (and increased locomotion), without reducing dopamine or serotonin transporter binding. This study supports the conclusion that factors other than monoamine terminal injury contribute to the methamphetamine-induced cognitive impairments.