Animal research suggests that the consolidation of fear and
extinction memories depends on N-methyl D-aspartate (NMDA)-
type glutamate receptors. Using a fear conditioning and extinction
paradigm in healthy normal volunteers, we show that postlearning
administration of the NMDA partial agonist D-cycloserine (DCS)
facilitates fear memory consolidation, evidenced behaviorally by
enhanced skin conductance responses, relative to placebo, for
presentations of a conditioned stimulus (CS) at a memory test
performed 72 h later. DCS also enhanced CS-evoked neural
responses in a posterior hippocampus/collateral sulcus region and
in the medial prefrontal cortex at test. Our data suggest a role for
NMDA receptors in regulating fear memory consolidation in humans
