title: Competition between engrams influences fear memory formation and recall.
abstract: Collections of cells called engrams are thought to represent memories. Although there has been progress in identifying and manipulating single engrams, little is known about how multiple engrams interact to influence memory. In lateral amygdala (LA), neurons with increased excitability during training outcompete their neighbors for allocation to an engram. We examined whether competition based on neuronal excitability also governs the interaction between engrams. Mice received two distinct fear conditioning events separated by different intervals. LA neuron excitability was optogenetically manipulated and revealed a transient competitive process that integrates memories for events occurring closely in time (coallocating overlapping populations of neurons to both engrams) and separates memories for events occurring at distal times (disallocating nonoverlapping populations to each engram).
authors.affiliation: Program in Neurosciences and Mental Health, Hospital for Sick Children, 555 University Avenue, Toronto, ON M5G 1X8, Canada. Department of Psychology, University of Toronto, Toronto, ON M5G 3G3, Canada. Institute of Medical Sciences, University of Toronto, Toronto, ON M5S 1A8, Canada. Department of Physiology, University of Toronto, Toronto, ON M5G 1X8, Canada.
authors.forename: Asim J
authors.initials: AJ
authors.lastname: Rashid
authors.affiliation: Program in Neurosciences and Mental Health, Hospital for Sick Children, 555 University Avenue, Toronto, ON M5G 1X8, Canada. Department of Psychology, University of Toronto, Toronto, ON M5G 3G3, Canada. Institute of Medical Sciences, University of Toronto, Toronto, ON M5S 1A8, Canada. Department of Physiology, University of Toronto, Toronto, ON M5G 1X8, Canada.
authors.forename: Chen
authors.initials: C
authors.lastname: Yan
authors.affiliation: Program in Neurosciences and Mental Health, Hospital for Sick Children, 555 University Avenue, Toronto, ON M5G 1X8, Canada. Department of Psychology, University of Toronto, Toronto, ON M5G 3G3, Canada. Institute of Medical Sciences, University of Toronto, Toronto, ON M5S 1A8, Canada. Department of Physiology, University of Toronto, Toronto, ON M5G 1X8, Canada.
authors.forename: Valentina
authors.initials: V
authors.lastname: Mercaldo
authors.affiliation: Program in Neurosciences and Mental Health, Hospital for Sick Children, 555 University Avenue, Toronto, ON M5G 1X8, Canada. Department of Psychology, University of Toronto, Toronto, ON M5G 3G3, Canada. Institute of Medical Sciences, University of Toronto, Toronto, ON M5S 1A8, Canada. Department of Physiology, University of Toronto, Toronto, ON M5G 1X8, Canada.
authors.forename: Hwa-Lin Liz
authors.initials: HL
authors.lastname: Hsiang
authors.affiliation: Program in Neurosciences and Mental Health, Hospital for Sick Children, 555 University Avenue, Toronto, ON M5G 1X8, Canada. Department of Psychology, University of Toronto, Toronto, ON M5G 3G3, Canada. Institute of Medical Sciences, University of Toronto, Toronto, ON M5S 1A8, Canada. Department of Physiology, University of Toronto, Toronto, ON M5G 1X8, Canada.
authors.forename: Sungmo
authors.initials: S
authors.lastname: Park
authors.affiliation: Program in Neurosciences and Mental Health, Hospital for Sick Children, 555 University Avenue, Toronto, ON M5G 1X8, Canada. Department of Psychology, University of Toronto, Toronto, ON M5G 3G3, Canada. Institute of Medical Sciences, University of Toronto, Toronto, ON M5S 1A8, Canada. Department of Physiology, University of Toronto, Toronto, ON M5G 1X8, Canada.
authors.forename: Christina J
authors.initials: CJ
authors.lastname: Cole
authors.affiliation: Program in Neurosciences and Mental Health, Hospital for Sick Children, 555 University Avenue, Toronto, ON M5G 1X8, Canada.
authors.forename: Antonietta
authors.initials: A
authors.lastname: De Cristofaro
authors.affiliation: Program in Neurosciences and Mental Health, Hospital for Sick Children, 555 University Avenue, Toronto, ON M5G 1X8, Canada.
authors.forename: Julia
authors.initials: J
authors.lastname: Yu
authors.affiliation: Department of Psychiatry and Behavioral Sciences, Stanford University, Stanford, CA 94305, USA.
authors.forename: Charu
authors.initials: C
authors.lastname: Ramakrishnan
authors.affiliation: Department of Psychiatry and Behavioral Sciences, Stanford University, Stanford, CA 94305, USA.
authors.forename: Soo Yeun
authors.initials: SY
authors.lastname: Lee
authors.affiliation: Department of Psychiatry and Behavioral Sciences, Stanford University, Stanford, CA 94305, USA.
authors.forename: Karl
authors.initials: K
authors.lastname: Deisseroth
authors.affiliation: Program in Neurosciences and Mental Health, Hospital for Sick Children, 555 University Avenue, Toronto, ON M5G 1X8, Canada. Department of Psychology, University of Toronto, Toronto, ON M5G 3G3, Canada. Institute of Medical Sciences, University of Toronto, Toronto, ON M5S 1A8, Canada. Department of Physiology, University of Toronto, Toronto, ON M5G 1X8, Canada. sheena.josselyn@sickkids.ca paul.frankland@sickkids.ca.
authors.forename: Paul W
authors.initials: PW
authors.lastname: Frankland
authors.affiliation: Program in Neurosciences and Mental Health, Hospital for Sick Children, 555 University Avenue, Toronto, ON M5G 1X8, Canada. Department of Psychology, University of Toronto, Toronto, ON M5G 3G3, Canada. Institute of Medical Sciences, University of Toronto, Toronto, ON M5S 1A8, Canada. Department of Physiology, University of Toronto, Toronto, ON M5G 1X8, Canada. sheena.josselyn@sickkids.ca paul.frankland@sickkids.ca.
authors.forename: Sheena A
authors.initials: SA
authors.lastname: Josselyn
mesh_terms: D000679:Amygdala / Q000166:cytology / Q000502:physiology*; D000818:Animals; D002450:Cell Communication; D003213:Conditioning, Psychological; D017362:Cyclic AMP Response Element-Binding Protein / Q000235:genetics / Q000378:metabolism; D005239:Fear / Q000502:physiology*; D005260:Female; D008297:Male; D000069077:Memory Consolidation / Q000502:physiology*; D011939:Mental Recall / Q000502:physiology*; D051379:Mice; D008810:Mice, Inbred C57BL; D009474:Neurons / Q000502:physiology*; D062308:Optogenetics
chemical_list: D017362:Cyclic AMP Response Element-Binding Protein