title: Somatostatin-positive interneurons in the dentate gyrus of mice provide local- and long-range septal synaptic inhibition.
abstract: Somatostatin-expressing-interneurons (SOMIs) in the dentate gyrus (DG) control formation of granule cell (GC) assemblies during memory acquisition. Hilar-perforant-path-associated interneurons (HIPP cells) have been considered to be synonymous for DG-SOMIs. Deviating from this assumption, we show two functionally contrasting DG-SOMI-types. The classical feedback-inhibitory HIPPs distribute axon fibers in the molecular layer. They are engaged by converging GC-inputs and provide dendritic inhibition to the DG circuitry. In contrast, SOMIs with axon in the hilus, termed hilar interneurons (HILs), provide perisomatic inhibition onto GABAergic cells in the DG and project to the medial septum. Repetitive activation of glutamatergic inputs onto HIPP cells induces long-lasting-depression (LTD) of synaptic transmission but long-term-potentiation (LTP) of synaptic signals in HIL cells. Thus, LTD in HIPPs may assist flow of spatial information from the entorhinal cortex to the DG, whereas LTP in HILs may facilitate the temporal coordination of GCs with activity patterns governed by the medial septum.
authors.affiliation: Systemic and Cellular Neurophysiology, Institute for Physiology I, University of Freiburg, Freiburg, Germany.|Faculty for Biology, University of Freiburg, Freiburg, Germany.
authors.forename: Mei
authors.initials: M
authors.lastname: Yuan
authors.affiliation: Systemic and Cellular Neurophysiology, Institute for Physiology I, University of Freiburg, Freiburg, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Meyer
authors.affiliation: Systemic and Cellular Neurophysiology, Institute for Physiology I, University of Freiburg, Freiburg, Germany.
authors.forename: Christoph
authors.initials: C
authors.lastname: Benkowitz
authors.affiliation: Systemic and Cellular Neurophysiology, Institute for Physiology I, University of Freiburg, Freiburg, Germany.
authors.forename: Shakuntala
authors.initials: S
authors.lastname: Savanthrapadian
authors.affiliation: Institute for Physiology, University of Kiel, Kiel, Germany.
authors.forename: Laura
authors.initials: L
authors.lastname: Ansel-Bollepalli
authors.affiliation: Institute for Physiology, University of Kiel, Kiel, Germany.
authors.forename: Angelica
authors.initials: A
authors.lastname: Foggetti
authors.affiliation: Institute for Physiology, University of Kiel, Kiel, Germany.
authors.forename: Peer
authors.initials: P
authors.lastname: Wulff
authors.affiliation: Systemic and Cellular Neurophysiology, Institute for Physiology I, University of Freiburg, Freiburg, Germany.
authors.forename: Pepe
authors.initials: P
authors.lastname: Alcami
authors.affiliation: Systemic and Cellular Neurophysiology, Institute for Physiology I, University of Freiburg, Freiburg, Germany.
authors.forename: Claudio
authors.initials: C
authors.lastname: Elgueta
authors.affiliation: Systemic and Cellular Neurophysiology, Institute for Physiology I, University of Freiburg, Freiburg, Germany.
authors.forename: Marlene
authors.identifier: 0000-0001-9741-1946
authors.initials: M
authors.lastname: Bartos
mesh_terms: D000818:Animals; D018891:Dentate Gyrus / Q000166:cytology*; D006728:Hormones / Q000032:analysis*; D007395:Interneurons / Q000737:chemistry* / Q000502:physiology*; D017774:Long-Term Potentiation; D051379:Mice; D009433:Neural Inhibition; D013004:Somatostatin / Q000032:analysis*; D009435:Synaptic Transmission
chemical_list: D006728:Hormones; D013004:Somatostatin
keywords: dentate gyrus; interneuron; medial septum; mouse; neuroscience; somatostatin; synaptic plasticity; synaptic transmission