title: Memory. Engram cells retain memory under retrograde amnesia.
abstract: Memory consolidation is the process by which a newly formed and unstable memory transforms into a stable long-term memory. It is unknown whether the process of memory consolidation occurs exclusively through the stabilization of memory engrams. By using learning-dependent cell labeling, we identified an increase of synaptic strength and dendritic spine density specifically in consolidated memory engram cells. Although these properties are lacking in engram cells under protein synthesis inhibitor-induced amnesia, direct optogenetic activation of these cells results in memory retrieval, and this correlates with retained engram cell-specific connectivity. We propose that a specific pattern of connectivity of engram cells may be crucial for memory information storage and that strengthened synapses in these cells critically contribute to the memory retrieval process.
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, Cambridge, MA 02139, USA. Howard Hughes Medical Institute, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
authors.forename: Tomás J
authors.initials: TJ
authors.lastname: Ryan
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, Cambridge, MA 02139, USA.
authors.forename: Dheeraj S
authors.initials: DS
authors.lastname: Roy
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, Cambridge, MA 02139, USA.
authors.forename: Michele
authors.initials: M
authors.lastname: Pignatelli
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, Cambridge, MA 02139, USA. Howard Hughes Medical Institute, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
authors.forename: Autumn
authors.initials: A
authors.lastname: Arons
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, Cambridge, MA 02139, USA. Howard Hughes Medical Institute, Massachusetts Institute of Technology, Cambridge, MA 02139, USA. tonegawa@mit.edu.
authors.forename: Susumu
authors.initials: S
authors.lastname: Tonegawa
mesh_terms: D000648:Amnesia, Retrograde / Q000139:chemically induced / Q000503:physiopathology*; D000679:Amygdala / Q000737:chemistry / Q000503:physiopathology; D000818:Animals; D003214:Conditioning, Classical; D003712:Dendrites / Q000737:chemistry / Q000473:pathology / Q000502:physiology*; D018891:Dentate Gyrus / Q000737:chemistry / Q000473:pathology / Q000503:physiopathology; D005456:Fluorescent Dyes / Q000032:analysis; D008164:Luminescent Proteins / Q000032:analysis; D057567:Memory, Long-Term / Q000502:physiology*; D051379:Mice; D009473:Neuronal Plasticity / Q000502:physiology; D011500:Protein Synthesis Inhibitors / Q000494:pharmacology; D013194:Staining and Labeling; D013569:Synapses / Q000502:physiology; D000097573:Red Fluorescent Protein
chemical_list: D005456:Fluorescent Dyes; D008164:Luminescent Proteins; D011500:Protein Synthesis Inhibitors; D000097573:Red Fluorescent Protein