D-Cycloserine into the BLA reverses the impairing effects of exposure to stress on the extinction of contextual fear, but not conditioned taste aversion

We investigated whether the N-methyl-D-aspartate (NMDA) receptor partial agonist D-cycloserine (DCS, 20 mu g/side) microinfused into the basolateral amygdala (BLA) would reverse stress-induced impairment of extinction in two aversive learning paradigms: contextual fear conditioning and conditioned taste aversion (CTA). We found that DCS in the BLA show differential involvement in the extinction of these two paradigms and in its modulation of stress-induced impairment of extinction. This may suggest that the dysfunctional extinction of fear and taste aversion following exposure to a stressful experience may be modulated by different mechanisms.