Mechanisms for phase shift of reactivated memory

点击翻译按钮获取中文摘要

Memory retrieval initiates two opposite processes; memory reconsolidation and extinction. Memory reconsolidation maintains or enhances fear memory, whereas memory extinction weakens fear memory. In this study, we tried to understand mechanisms by which the fate of memory is determined after retrieval by analyzing activation of transcription factor CREB, ERK and proteasome-dependent protein degradation in the hippocampus, amygdala and mPFC. We identified reconsolidation neurons and extinction neurons that display distinct biochemical features in reconsolidation and extinction phases, respectively. More importantly, in the extinction phase, reconsolidation neurons were inactivated while extinction neurons activated ERK signaling pathway in the hippocampus. From these observations, we concluded that hippocampus plays key roles in the phase shift from reconsolidation to extinction following memory retrieval.