Hippocampal memory traces are differentially modulated by experience, time, and adult neurogenesis

Christine A. Denny, Mazen A. Kheirbek, Eva L. Alba, Kenji F. Tanaka, Rebecca A. Brachman, Kimberly B. Laughman, Nicole K. Tomm, Gergely F. Turi, Attila Losonczy, René Hen

Research output: Contribution to journalArticlepeer-review

345 Citations (Scopus)


Memory traces are believed to be ensembles of cells used to store memories. To visualize memory traces, we created a transgenic line that allows for the comparison between cells activated during encoding and expression of a memory. Mice re-exposed to a fear-inducing context froze more and had a greater percentage of reactivated cells in the dentate gyrus (DG) and CA3 than mice exposed to a novel context. Over time, these differences disappeared, in keeping with the observation that memories become generalized. Optogenetically silencing DG or CA3 cells that were recruited during encoding of a fear-inducing context prevented expression of the corresponding memory. Mice with reduced neurogenesis displayed less contextual memory and less reactivation in CA3but, surprisingly, normal reactivation in the DG. These studies suggest that distinct memory traces are located in the DG and in CA3 but that the strength of the memory is related to reactivation in CA3.

Original languageEnglish
Pages (from-to)189-201
Number of pages13
Issue number1
Publication statusPublished - 2014 Jul 2

ASJC Scopus subject areas

  • General Neuroscience


Dive into the research topics of 'Hippocampal memory traces are differentially modulated by experience, time, and adult neurogenesis'. Together they form a unique fingerprint.

Cite this