Finding the engram.
Many attempts have been made to localize the physical trace of a memory, or engram, in the brain. However, until recently, engrams have remained largely elusive. In this Review, we develop four defining criteria that enable us to critically assess the recent progress that has been made towards finding the engram. Recent 'capture' studies use novel approaches to tag populations of neurons that are active during memory encoding, thereby allowing these engram-associated neurons to be manipulated at later times. We propose that findings from these capture studies represent considerable progress in allowing us to observe, erase and express the engram.
Program in Neurosciences &Mental Health, The Hospital for Sick Children (SickKids), 555 University Avenue, Toronto, Ontario M5G 1X8, Canada.|Department of Psychology, University of Toronto, 100 St. George Street, Toronto, Ontario M5S 3GM, Canada.|Department of Physiology, University of Toronto, 1 King's College Circle, Toronto, Ontario M5S 1A8, Canada.|Institute of Medical Science, University of Toronto, 1 King's College Circle, Toronto, Ontario M5S 1A8, Canada.
Sheena A
SA
Josselyn
Brain and Mind Institute, University of Western Ontario, Natural Sciences Centre, London, Ontario N6A 5B7, Canada.|Department of Psychology, University of Western Ontario, London, Ontario N6A 5C2, Canada.
Stefan
S
Köhler
Program in Neurosciences &Mental Health, The Hospital for Sick Children (SickKids), 555 University Avenue, Toronto, Ontario M5G 1X8, Canada.|Department of Psychology, University of Toronto, 100 St. George Street, Toronto, Ontario M5S 3GM, Canada.|Department of Physiology, University of Toronto, 1 King's College Circle, Toronto, Ontario M5S 1A8, Canada.|Institute of Medical Science, University of Toronto, 1 King's College Circle, Toronto, Ontario M5S 1A8, Canada.
Paul W
PW
Frankland
D000818:Animals; D003213:Conditioning, Psychological / Q000502:physiology*; D005239:Fear / Q000502:physiology* / Q000523:psychology; D006624:Hippocampus / Q000502:physiology*; D006801:Humans; D008568:Memory / Q000502:physiology*; D009474:Neurons / Q000502:physiology*