Unlocking memory: The role of epigenetics in memory

Our experiences leave traces in the brain, which are stored in small groups of cells called "engrams".Engrams are believed to contain memory information and are reactivated when we remember. This is what makes it so interesting for research on memory and aging or trauma-related amnesia.

Our experiences leave imprints in the brain that are stored in small groups called "engrams".When trying to store memory information and remember it, it is now memory, memory, memory, memory, and memory related memory loss.

At the same time, scientists know that the biology of learning is accompanied by epigenetic changes, which refer to the way cells regulate genes by adding chemical "post-it notes" to DNA.

But the question of whether the genetic state of a single gene can cause changes in memory has remained unanswered.

The team led by Professor Johannes Gräff from EPFL's Neuroepigenetics Laboratory combined CRISPR-based gene control with the engram cell-tagging technique in mice.They focused on Arc, a gene that helps neurons adjust connections with other neurons.The team focused on the Arc control region and asked whether flicking an epigenetic "switch" could directly alter memory.

Change "Epignetic"

Researchers developed special CRISPR-based tools that could reduce or increase Arc activity in memory neurons.Some, like the KRAB-MeCP2 device, were designed to turn off gene activity by adding repressive signals that make the DNA less accessible, while others opened up the DNA and turned the gene on.These devices were essentially an "epigenetic switch" for the Arc gene.

Then they use bad diseases to introduce these habits in the gym, a tie is a tie, the cursor is a match for the competitor.Correct and reset the memory location.

The study showed that epigenetic silencing of Arc in engram cells made the mice unable to learn, while a boost made their memory stronger.These changes can be reversed in the same animal, showing that this epigenetic "switch" can turn memory expression up or down.Even memories that were already several days old and normally difficult to change could be changed.At the molecular level, the editing caused changes in gene activity and DNA packaging that matched the behavioral effects.

Manage memory expression

This study is the first to directly demonstrate that altering the epigenetic state of memory cells is necessary and sufficient to regulate memory expression.This opens up a new way to explore how memories are stored and modified, which may ultimately be relevant to humans.

In the future, similar approaches could help researchers better understand conditions where memory processing goes awry, such as traumatic memories in PTSD, drug-related memories in addiction, or memory problems that appear in neurodegenerative diseases.

- EPFL Bioinformatics Competence Center

- EPFL Council of the Research Center for Neuroscience

Koda, D. M., et al.(2025).Cell-locus-specific epigenetic editing of memory expression.Nature Genetics.doi.org/10.1038/s41588-025-02368-y