Venue: Centre Broca Nouvelle-Aquitaine
René HEN
Columbia University, New York, USA
Invited by Nicolas Blin (Abrous’ Lab – Magendie)
Title
Adult Hippocampal neurogenesis, pattern separation, and overgeneralization
Abstract
Adult born granule cells (abGCs) have been implicated in memory discrimination through a neural computation known as pattern separation. We have examined how chronic ablation or acute chemogenetic silencing of abGCs affects the activity of mature granule cells (mGCs) using in vivo Ca2+ imaging. In both cases we observed altered remapping of mGCs. Rather than broadly modulating the activity of all mGCs, abGCs promote the remapping of place cells’ firing fields while increasing rate remapping of mGCs representing sensory cues. In turn, these remapping deficits are associated with behavioral impairments in animals’ ability to correctly identify new goal locations. Thus, abGCs facilitate pattern separation through the formation of non-overlapping representations for identical sensory cues encountered in different locations. In the absence of abGCs the dentate gyrus shifts to a state dominated by cue information, a situation that is consistent with the overgeneralization often observed in anxiety or age related disorders.
Publications
Tuncdemir SN, Grosmark AD, Chung H, Luna VM, Lacefield CO, Losonczy A, and Hen R. Adult born granule cells facilitate remapping of spatial and non-spatial representations in the dentate gyrus. 2023, Neuron. In press (online, Oct 10).
Stefanini F, Kushnir L, Jimenez JC, Jennings JH, Woods NI, Stuber GD, Kheirbek MA, Hen R, Fusi S. (2020) A Distributed Neural Code in the Dentate Gyrus and in CA1. Neuron.107(4):703-716.
Luna VM, Anacker C, Burghardt N, Khandaker H, Andreu V, Millette A, Leary P,
Ravenelle R, Jimenez J, Mastrodonato A, Denny CA, Fenton A, Scharfman H, Hen R. (2019); Adult-born hippocampal neurons bidirectionally modulate entorhinal inputs into the dentate gyrus. Science. 364(6440):578-583.
PhD seminars are organized by the NBA, Bordeaux Neurocampus, and the Bordeaux Neurocampus Graduate Program