title: Sequential learning during contextual fear conditioning guides the rate of systems consolidation: Implications for consolidation of multiple memory traces.
abstract: Systems consolidation has been described as a time-dependent reorganization process involving the neocortical and hippocampal networks underlying memory storage and retrieval. Previous studies of our lab were able to demonstrate that systems consolidation is a dynamic process, rather than a merely passive, time-dependent phenomenon. Here, we studied the influence of sequential learning in contextual fear conditioning (CFC) with different training intensities in the time-course of hippocampal dependency and contextual specificity. We found that sequential learning with high-intensity shocks during CFC induces generalization of the first learning (context A) and maintains contextual specificity of the second learning (context B) 15 days after acquisition. Moreover, subsequent experiences reorganize brain structures involved in retrieval, accelerating the involvement of cortical structures and diminishing the hippocampal participation. Exposure to original context before novelty seems to only induce context specificity in hippocampal-dependent memories. We propose that systems consolidation could be considered a potential biological mechanism for reducing possible interferences between similar memory traces. © 2017 Wiley Periodicals, Inc.
authors.affiliation: Laboratório de Neurobiologia da Memória, Biophysics Department, Biosciences Institute, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil.|Institute of Health Sciences, Graduate Program in Neuroscience, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil.
authors.forename: Lizeth K
authors.initials: LK
authors.lastname: Pedraza
authors.affiliation: Institute of Health Sciences, Graduate Program in Neuroscience, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil.|Laboratório de Psicobiologia e Neurocomputação, Biophysics Department, Biosciences Institute, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil.
authors.forename: Rodrigo O
authors.initials: RO
authors.lastname: Sierra
authors.affiliation: Institute of Health Sciences, Graduate Program in Neuroscience, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil.|Laboratório de Psicobiologia e Neurocomputação, Biophysics Department, Biosciences Institute, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil.
authors.forename: Ana P
authors.initials: AP
authors.lastname: Crestani
authors.affiliation: Institute of Health Sciences, Graduate Program in Neuroscience, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil.|Laboratório de Psicobiologia e Neurocomputação, Biophysics Department, Biosciences Institute, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil.
authors.forename: Jorge A
authors.initials: JA
authors.lastname: Quillfeldt
authors.affiliation: Laboratório de Neurobiologia da Memória, Biophysics Department, Biosciences Institute, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil.|Institute of Health Sciences, Graduate Program in Neuroscience, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil.
authors.forename: Lucas
authors.identifier: 0000-0002-0472-903X
authors.initials: L
authors.lastname: de Oliveira Alvares
mesh_terms: D000818:Animals; D002408:Catheters, Indwelling; D003213:Conditioning, Psychological / Q000187:drug effects / Q000502:physiology*; D004597:Electroshock; D005239:Fear / Q000187:drug effects / Q000502:physiology*; D046352:Freezing Reaction, Cataleptic / Q000187:drug effects / Q000502:physiology; D058785:GABA-A Receptor Agonists / Q000494:pharmacology; D006179:Gyrus Cinguli / Q000187:drug effects / Q000502:physiology; D006624:Hippocampus / Q000187:drug effects / Q000502:physiology; D008297:Male; D000069077:Memory Consolidation / Q000187:drug effects / Q000502:physiology*; D009118:Muscimol / Q000494:pharmacology; D009483:Neuropsychological Tests; D011897:Random Allocation; D017208:Rats, Wistar; D011963:Receptors, GABA-A / Q000378:metabolism; D013997:Time Factors; D014163:Transfer, Psychology / Q000187:drug effects / Q000502:physiology
chemical_list: D058785:GABA-A Receptor Agonists; D011963:Receptors, GABA-A; D009118:Muscimol
keywords: anterior cingulate cortex; hippocampus; memory precision; sequential learning; systems consolidation