DG-CA3 circuitry mediates hippocampal representations of latent information.

TitleDG-CA3 circuitry mediates hippocampal representations of latent information.
Publication TypeJournal Article
Year of Publication2020
AuthorsKeinath AT, Nieto-Posadas A, Robinson JC, Brandon MP
JournalNat Commun
Date Published2020 06 15
KeywordsAnimals, CA1 Region, Hippocampal, CA3 Region, Hippocampal, Dentate Gyrus, Male, Memory, Mice, Inbred C57BL, Models, Neurological, Pattern Recognition, Physiological

Survival in complex environments necessitates a flexible navigation system that incorporates memory of recent behavior and associations. Yet, how the hippocampal spatial circuit represents latent information independent of sensory inputs and future goals has not been determined. To address this, we image the activity of large ensembles in subregion CA1 via wide-field fluorescent microscopy during a novel behavioral paradigm. Our results demonstrate that latent information is represented through reliable firing rate changes during unconstrained navigation. We then hypothesize that the representation of latent information in CA1 is mediated by pattern separation/completion processes instantiated upstream within the dentate gyrus (DG) and CA3 subregions. Indeed, CA3 ensemble recordings reveal an analogous code for latent information. Moreover, selective chemogenetic inactivation of DG-CA3 circuitry completely and reversibly abolishes the CA1 representation of latent information. These results reveal a causal and specific role of DG-CA3 circuitry in the maintenance of latent information within the hippocampus.

Alternate JournalNat Commun
PubMed ID32541860
PubMed Central IDPMC7296021
Grant List367017 / / CIHR / Canada
377074 / / CIHR / Canada