title: Consolidation and reconsolidation are impaired by oral propranolol administered before but not after memory (re)activation in humans.
abstract: Propranolol administered immediately after learning or after recall has been found to impair memory consolidation or reconsolidation (respectively) in animals, but less reliably so in humans. Since reconsolidation impairment has been proposed as a treatment for mental disorders that have at their core an emotional memory, it is desirable to understand how to reliably reduce the strength of pathogenic memories in humans. We postulated that since humans (unlike experimental animals) typically receive propranolol orally, this introduces a delay before this drug can exert its memory impairment effects, which may render it less effective. As a means to test this, in two double-blind placebo-controlled experiments, we examined the capacity of propranolol to impair consolidation and reconsolidation as a function of timing of ingestion in healthy subjects. In Experiment 1, (n=36), propranolol administered immediately after learning or recall failed to impair the consolidation or reconsolidation of the memory of a standardized slideshow with an accompanying emotional story. In Experiment 2 (n=50), propranolol given 60-75min before learning or recall successfully impaired memory consolidation and reconsolidation. These results suggest that it is possible to achieve reliable memory impairment in humans if propranolol is given before learning or before recall, but not after.
authors.affiliation: Douglas Mental Health University Institute, 6875 Lasalle Boulevard, H4H 1R3 Montréal, Québec, Canada.
authors.forename: Émilie
authors.initials: É
authors.lastname: Thomas
authors.affiliation: Douglas Mental Health University Institute, 6875 Lasalle Boulevard, H4H 1R3 Montréal, Québec, Canada.
authors.forename: Daniel
authors.initials: D
authors.lastname: Saumier
authors.affiliation: Department of Psychiatry, Massachusetts General Hospital and Harvard Medical School, 120 Second Avenue, Charlestown, MA 02129, USA.
authors.forename: Roger K
authors.initials: RK
authors.lastname: Pitman
authors.affiliation: Douglas Mental Health University Institute, 6875 Lasalle Boulevard, H4H 1R3 Montréal, Québec, Canada; Department of Psychiatry, McGill University, 1033 Pine Avenue West, H3A 1A1 Montréal, Québec, Canada.
authors.forename: Jacques
authors.initials: J
authors.lastname: Tremblay
authors.affiliation: Douglas Mental Health University Institute, 6875 Lasalle Boulevard, H4H 1R3 Montréal, Québec, Canada; Department of Psychiatry, McGill University, 1033 Pine Avenue West, H3A 1A1 Montréal, Québec, Canada; Department of Neurology and Neurosurgery, and Integrated Program in Neurosciences, McGill University, 3801 University Street, H3A 2B4 Montréal, Québec, Canada. Electronic address: alain.brunet@mcgill.ca.
authors.forename: Alain
authors.initials: A
authors.lastname: Brunet
mesh_terms: D000293:Adolescent; D000319:Adrenergic beta-Antagonists / Q000494:pharmacology*; D000328:Adult; D004311:Double-Blind Method; D004644:Emotions / Q000187:drug effects; D005260:Female; D006801:Humans; D008297:Male; D008568:Memory / Q000187:drug effects*; D000069077:Memory Consolidation / Q000187:drug effects*; D008875:Middle Aged; D011433:Propranolol / Q000494:pharmacology*; D055815:Young Adult
chemical_list: D000319:Adrenergic beta-Antagonists; D011433:Propranolol
keywords: Emotional memory; Propranolol; Reconsolidation