The international journal of neuropsychopharmacology
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Int. J. Neuropsychopharmacol. · Jul 2009
Randomized Controlled TrialHaloperidol counteracts the ketamine-induced disruption of processing negativity, but not that of the P300 amplitude.
Antagonists of the N-methyl-D-aspartate (NMDA) receptors such as ketamine, induce abnormalities in healthy subjects similar to those found in schizophrenia. However, recent evidence, suggests that most of the currently known NMDA antagonists have a broader receptor profile than originally thought. Besides exerting an antagonistic effect on NMDA receptors, they have agonistic effects on dopamine D2 receptors. ⋯ In addition, ketamine reduced both P300 amplitude and processing negativity. In contrast to the P300 amplitude, the disruptive effects of ketamine on processing negativity could be prevented by pretreatment with haloperidol. The current results suggest that ketamine reduced P300 amplitude by its antagonistic effect on glutamatergic activity, while it reduced processing negativity by its agonistic effect on dopaminergic D2 activity.