Exploring the dynamic nature of memory to eliminate pathological memories

Abstracts / IBRO Reports 6 (2019) S6-S53of optogenetic activation and inactivation of them were examined during memory retrieval.Inactivation of fear engram neurons during retrieval erased contextual fear memory, perhaps, by blocking memory reconsolidation, whereas activation of these engrams during retrieval blocked acquisition and consolidation of fear memory extinction.These results suggest that modulation of fear memory engram cells are crucial processes to determine the fate of memory, reconsolidation or extinction.We also identified fear and extinction engram neurons in the amygdala and mPFC.Interestingly, distinct fear and extinction engram neurons were observed in the amygdala, while single neuronal fear/extinction engram neurons was observed in the mPFC.We are now characterizing these engram neurons using optogenetics.