Abstract
Fully consolidated fear memories can be maintained or inhibited by retrieval-dependent mechanisms depending on the degree of re-exposure to fear cues. Short exposures promote memory maintenance through reconsolidation, and long exposures promote inhibition through extinction. Little is known about the neural mechanisms by which increasing cue exposure overrides reconsolidation and instead triggers extinction. Using auditory fear conditioning in male rats, we analyzed the role of a molecular mechanism common to reconsolidation and extinction of fear, ERK1/2 activation within the basolateral amygdala (BLA), after intermediate conditioned stimulus (CS) exposure events. We show that an intermediate re-exposure (four CS presentations) failed to activate ERK1/2 in the BLA, suggesting the absence of reconsolidation or extinction mechanisms. Supporting this hypothesis, pharmacologically inhibiting the BLA ERK1/2-dependent signaling pathway in conjunction with four CS presentations had no effect on fear expression, and the NMDA receptor partial agonist d-cycloserine, which enhanced extinction and ERK1/2 activation in partial extinction protocols (seven CSs), had no behavioral or molecular effect when given in association with four CS pr...Continue Reading
Citations
Jan 19, 2019·Psychopharmacology·Emma N Cahill, Amy L Milton
Jun 17, 2020·Psychological Medicine·Grace GaleRavi K Das
May 7, 2019·Frontiers in Molecular Neuroscience·Maria C KrawczykMariano M Boccia
Oct 23, 2018·Frontiers in Molecular Neuroscience·Jorge H Medina, Haydee Viola
Mar 11, 2020·Frontiers in Behavioral Neuroscience·Eloise J KuijerAmy L Milton
Mar 8, 2019·Frontiers in Molecular Neuroscience·Mario Rafael Pagani, Emiliano Merlo
Dec 12, 2019·F1000Research·Amy L Milton
Aug 18, 2018·Learning & Memory·Marc T J Exton-McGuinness, Amy L Milton
Sep 27, 2020·Neuroscience·Santiago A MerloEmiliano Merlo
Jan 25, 2021·Behavioural Brain Research·Santiago Ojea RamosMariana Feld
Nov 3, 2020·Frontiers in Behavioral Neuroscience·Zuzana VaverkováEmiliano Merlo
Mar 17, 2021·Neuroscience and Biobehavioral Reviews·Lucas de Oliveira Alvares, Fabricio H Do-Monte
Apr 13, 2021·IBRO Neuroscience Reports·Kurrey Khuleshwari, Paramanik Vijay