Aging changes memory-associated neuronal ensembles and gene expression in mice
Published in Biology, Brain Activity, Brain/Neurology, Journals, Memory.
Published October 31, 2026.
A new study in Nature Communications examines how aging changes the neuronal ensembles involved in memory, often called engrams. Researchers compared contextual fear-memory encoding and recall in young and aged mice.
Nuclear tagging and FOS-based activity mapping revealed age-related differences in the activation, distribution and relationships between memory-associated ensembles across brain regions. Nuclear sorting and single-nucleus RNA sequencing then characterized gene-expression patterns in the activated cells.
In aged mice, recall-associated ensembles showed reduced reactivation and less coordinated activity-dependent transcription, particularly in the dentate gyrus. The findings were consistent with greater inhibitory engagement by somatostatin-expressing interneurons.
The work links altered memory-trace organization with molecular changes during aging. It does not demonstrate that changing those interneurons restores memory, nor establish a treatment for human cognitive decline.
The experiments concern a specific memory task in mice. Their relevance to other memory types, human aging and interventions requires further testing.
Source: Fuentes-Ramos, M., Paraíso-Luna, J., Torres-Raves, P. et al., Nature Communications, October 31, 2026. Read the original study.