title: Hippocampal Somatostatin Interneurons Control the Size of Neuronal Memory Ensembles.
abstract: Hippocampal neurons activated during encoding drive the recall of contextual fear memory. Little is known about how such ensembles emerge during acquisition and eventually form the cellular engram. Manipulating the activity of granule cells (GCs) of the dentate gyrus (DG), we reveal a mechanism of lateral inhibition that modulates the size of the cellular engram. GCs engage somatostatin-positive interneurons that inhibit the dendrites of surrounding GCs. Our findings reveal a microcircuit within the DG that controls the size of the cellular engram and the stability of contextual fear memory.
authors.affiliation: Department of Basic Neurosciences, Faculty of Medicine, University of Geneva, Michel-Servet 1, 1211 Geneva-4, Switzerland.
authors.forename: Thomas
authors.initials: T
authors.lastname: Stefanelli
authors.affiliation: Department of Basic Neurosciences, Faculty of Medicine, University of Geneva, Michel-Servet 1, 1211 Geneva-4, Switzerland.
authors.forename: Cristina
authors.initials: C
authors.lastname: Bertollini
authors.affiliation: Department of Basic Neurosciences, Faculty of Medicine, University of Geneva, Michel-Servet 1, 1211 Geneva-4, Switzerland; Service of Neurology, Geneva University Hospital, Gabrielle-Perret-Gentil 4, 1211 Geneva-4, Switzerland.
authors.forename: Christian
authors.initials: C
authors.lastname: Lüscher
authors.affiliation: Department of Basic Neurosciences, Faculty of Medicine, University of Geneva, Michel-Servet 1, 1211 Geneva-4, Switzerland.
authors.forename: Dominique
authors.initials: D
authors.lastname: Muller
authors.affiliation: Department of Basic Neurosciences, Faculty of Medicine, University of Geneva, Michel-Servet 1, 1211 Geneva-4, Switzerland. Electronic address: pablo.mendez@unige.ch.
authors.forename: Pablo
authors.initials: P
authors.lastname: Mendez
mesh_terms: D000200:Action Potentials / Q000235:genetics; D000818:Animals; D002452:Cell Count; D048429:Cell Size; D000075402:Channelrhodopsins; D003213:Conditioning, Psychological / Q000502:physiology; D018891:Dentate Gyrus / Q000166:cytology*; D005239:Fear / Q000502:physiology; D007395:Interneurons / Q000502:physiology*; D008164:Luminescent Proteins / Q000235:genetics; D018782:Maze Learning; D008568:Memory / Q000502:physiology*; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D010320:Parvalbumins / Q000235:genetics / Q000378:metabolism; D018408:Patch-Clamp Techniques; D013004:Somatostatin / Q000235:genetics / Q000378:metabolism*; D013037:Spatial Behavior / Q000502:physiology; D018709:Statistics, Nonparametric
chemical_list: D000075402:Channelrhodopsins; D008164:Luminescent Proteins; D010320:Parvalbumins; D013004:Somatostatin