title: Propranolol-induced Impairment of Contextual Fear Memory Reconsolidation in Rats: A similar Effect on Weak and Strong Recent and Remote Memories.
abstract: BACKGROUND
  Previous studies have demonstrated that the β-adrenergic receptor antagonist propranolol impairs fear memory reconsolidation in experimental animals. There are experimental parameters such as the age and the strength of memory that can interact with pharmacological manipulations of memory reconsolidation. In this study, we investigated the ability of the age and the strength of memory to influence the disrupting effects of propranolol on fear memory reconsolidation in rats.
  
  
  METHODS
  The rats were trained in a contextual fear conditioning using two (weak training) or five (strong training) footshocks (1mA). Propranolol (10mg/kg) injection was immediately followed retrieval of either a one-day recent (weak or strong) or 36-day remote (weak or strong) contextual fear memories.
  
  
  RESULTS
  We found that propranolol induced a long-lasting impairment of subsequent expression of recent and remote memories with either weak or strong strength. We also found no memory recovery after a weak reminder shock. Furthermore, no significant differences were found on the amount of memory deficit induced by propranolol among memories with different age and strength.
  
  
  CONCLUSIONS
  Our data suggest that the efficacy of propranolol in impairing fear memory reconsolidation is not limited to the age or strength of the memory.
authors.affiliation: Islamic Azad University, Damghan Branch, Damghan, Iran.
authors.forename: Fatemeh
authors.initials: F
authors.lastname: Taherian
authors.affiliation: Laboratory of Learning and Memory, Research Center and Department of Physiology, School of Medicine, Semnan University of Medical Sciences, Semnan, Iran.
authors.forename: Abbas Ali
authors.initials: AA
authors.lastname: Vafaei
authors.affiliation: Islamic Azad University, Damghan Branch, Damghan, Iran.
authors.forename: Gholam Hassan
authors.initials: GH
authors.lastname: Vaezi
authors.affiliation: Islamic Azad University, Damghan Branch, Damghan, Iran.
authors.forename: Sharaf
authors.initials: S
authors.lastname: Eskandarian
authors.affiliation: Laboratory of Learning and Memory, Research Center and Department of Physiology, School of Medicine, Semnan University of Medical Sciences, Semnan, Iran.
authors.forename: Adel
authors.initials: A
authors.lastname: Kashef
authors.affiliation: Laboratory of Learning and Memory, Research Center and Department of Physiology, School of Medicine, Semnan University of Medical Sciences, Semnan, Iran.
authors.forename: Ali
authors.initials: A
authors.lastname: Rashidy-Pour
keywords: Fear Conditioning; Memory Age; Memory Reconsolidation; Memory Strength; Propranolol