Logo image
Mystery of the Memory Engram: History, current knowledge, and unanswered questions
Journal article   Open access   Peer reviewed

Mystery of the Memory Engram: History, current knowledge, and unanswered questions

M.R Lopez, S.M.H Wasberg, C.M Gagliardi, M.E Normandin and I.A Muzzio
Neuroscience and biobehavioral reviews, Vol.159, 105574
04/2024
DOI: 10.1016/j.neubiorev.2024.105574
PMID: 38331127
url
https://doi.org/10.1016/j.neubiorev.2024.105574View
Published (Version of record) Open Access

Abstract

The quest to understand the memory engram has intrigued humans for centuries. Recent technological advances, including genetic labeling, imaging, optogenetic and chemogenetic techniques, have propelled the field of memory research forward. These tools have enabled researchers to create, and erase memory components. While these innovative techniques have yielded invaluable insights, they often focus on specific elements of the memory trace. Genetic labeling may rely on a particular immediate early gene as a marker of activity, optogenetics may activate or inhibit one specific type of neuron, and imaging may capture activity snapshots in a given brain region at specific times. Yet, memories are multifaceted, involving diverse arrays of neuronal subpopulations, circuits, and regions that work in concert to create, store, and retrieve information. Consideration of contributions of both excitatory and inhibitory neurons, micro and macro circuits across brain regions, the dynamic nature of active ensembles, and representational drift is crucial for a comprehensive understanding of the complex nature of memory. •Memory engrams include micro/macro circuits across cell ensembles and brain regions•Memory involves heterogeneous contributions of inhibitory/excitatory subpopulations•Hippocampus and mPFC engrams display representational drift and are dynamic•Single approaches are insufficient for understanding multifaceted memory engrams.
consolidation engrams hippocampus medial prefrontal cortex memory place cells remote memory system consolidation

Details

Metrics

Logo image