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

ABSTRACT: 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 CA3 but, surprisingly, normal reactivati

SUBMITTER: Denny CA 

PROVIDER: S-EPMC4169172 | biostudies-literature | 2014 Jul

REPOSITORIES: biostudies-literature