title: Ventral CA1 neurons store social memory.
abstract: The medial temporal lobe, including the hippocampus, has been implicated in social memory. However, it remains unknown which parts of these brain regions and their circuits hold social memory. Here, we show that ventral hippocampal CA1 (vCA1) neurons of a mouse and their projections to nucleus accumbens (NAc) shell play a necessary and sufficient role in social memory. Both the proportion of activated vCA1 cells and the strength and stability of the responding cells are greater in response to a familiar mouse than to a previously unencountered mouse. Optogenetic reactivation of vCA1 neurons that respond to the familiar mouse enabled memory retrieval and the association of these neurons with unconditioned stimuli. Thus, vCA1 neurons and their NAc shell projections are a component of the storage site of social memory.
authors.affiliation: RIKEN-MIT Center for Neural Circuit Genetics at the Picower Institute for Learning and Memory, Department of Biology and Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology (MIT), Cambridge, MA 02139, USA.
authors.forename: Teruhiro
authors.initials: T
authors.lastname: Okuyama
authors.affiliation: RIKEN-MIT Center for Neural Circuit Genetics at the Picower Institute for Learning and Memory, Department of Biology and Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology (MIT), Cambridge, MA 02139, USA.
authors.forename: Takashi
authors.initials: T
authors.lastname: Kitamura
authors.affiliation: RIKEN-MIT Center for Neural Circuit Genetics at the Picower Institute for Learning and Memory, Department of Biology and Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology (MIT), Cambridge, MA 02139, USA.
authors.forename: Dheeraj S
authors.initials: DS
authors.lastname: Roy
authors.affiliation: Brain Science Institute, RIKEN, Saitama, 351-0198, Japan.
authors.forename: Shigeyoshi
authors.initials: S
authors.lastname: Itohara
authors.affiliation: RIKEN-MIT Center for Neural Circuit Genetics at the Picower Institute for Learning and Memory, Department of Biology and Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology (MIT), Cambridge, MA 02139, USA. Brain Science Institute, RIKEN, Saitama, 351-0198, Japan. Howard Hughes Medical Institute at MIT, Cambridge, MA 02139, USA. tonegawa@mit.edu.
authors.forename: Susumu
authors.initials: S
authors.lastname: Tonegawa
mesh_terms: D000818:Animals; D056547:CA1 Region, Hippocampal / Q000166:cytology / Q000502:physiology*; D002552:Cerebral Ventricles / Q000166:cytology / Q000502:physiology*; D005260:Female; D008297:Male; D011939:Mental Recall / Q000502:physiology*; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D009714:Nucleus Accumbens / Q000166:cytology / Q000502:physiology; D062308:Optogenetics; D017966:Pyramidal Cells / Q000502:physiology*; D012919:Social Behavior