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RESEARCH PRODUCT

Mechanisms Underlying Memory Consolidation by Adult-Born Neurons During Sleep

Masanori SakaguchiPablo Vergara

subject

0301 basic medicinehippocampusMini Reviewtheta oscillationHippocampusEngramBiologyHippocampal formationOptogeneticslcsh:RC321-57103 medical and health sciencesCellular and Molecular Neuroscience0302 clinical medicineFear conditioningoptogeneticslcsh:Neurosciences. Biological psychiatry. Neuropsychiatrysynaptic plasticityNeurogenesismemory consolidation030104 developmental biologyCellular NeuroscienceSynaptic plasticitycalcium-imagingMemory consolidationREM sleepadult-neurogenesisNeuroscience030217 neurology & neurosurgery

description

The mammalian hippocampus generates new neurons that incorporate into existing neuronal networks throughout the lifespan, which bestows a unique form of cellular plasticity to the memory system. Recently, we found that hippocampal adult-born neurons (ABNs) that were active during learning reactivate during subsequent rapid eye movement (REM) sleep and provided causal evidence that ABN activity during REM sleep is necessary for memory consolidation. Here, we describe the potential underlying mechanisms by highlighting distinct characteristics of ABNs including decoupled firing from local oscillations and ability to undergo profound synaptic remodeling in response to experience. We further discuss whether ABNs constitute the conventional definition of engram cells by focusing on their active and passive roles in the memory system. This synthesis of evidence helps advance our thinking on the unique mechanisms by which ABNs contribute to memory consolidation.

https://doi.org/10.3389/fncel.2020.594401