The temporal specificity of the switch from NMDAr-dependent extinction to NMDAr-independent re-extinction

Recent findings show that the switch from NMDAr-dependent extinction to NMDAr-independent re-extinction is both context and stimulus specific. In this study we examined whether this switch was temporally specific as well. Re-extinction was found to be NMDAr-independent when it occurred 2 days after initial extinction but NMDAr-dependent when it occurred 21 days following initial extinction, thereby illustrating the importance of time as a type of context that modulates the mechanisms involved in extinction.