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Potent attenuation of context fear by extinction training contiguous with acquisition

Studies on the behavioral mechanisms underlying contextual fear conditioning (CFC) have demonstrated the importance of preshock context exposure in the formation of aversive context memories. However, there has been comparatively little investigation of the effects of context exposure immediately af...

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Detalles Bibliográficos
Autores principales: Bernier, Brian E., Lacagnina, Anthony F., Drew, Michael R.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Cold Spring Harbor Laboratory Press 2015
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4274325/
https://www.ncbi.nlm.nih.gov/pubmed/25512575
http://dx.doi.org/10.1101/lm.036673.114
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author Bernier, Brian E.
Lacagnina, Anthony F.
Drew, Michael R.
author_facet Bernier, Brian E.
Lacagnina, Anthony F.
Drew, Michael R.
author_sort Bernier, Brian E.
collection PubMed
description Studies on the behavioral mechanisms underlying contextual fear conditioning (CFC) have demonstrated the importance of preshock context exposure in the formation of aversive context memories. However, there has been comparatively little investigation of the effects of context exposure immediately after the shock. Some models predict that nonreinforced context exposure at the end of the acquisition session will strongly influence the strength of conditioning and/or recruit distinct neural mechanisms relative to extinction after acquisition. Here we investigate the effects of manipulating postshock context exposure on CFC in mice. Prolonging the period of context exposure immediately following the shock caused a significant and durable reduction in conditioned fear. This immediate postshock context exposure was more effective at attenuating conditioned fear than was an equivalent amount of context exposure a day or more after acquisition. The results suggest that nonreinforced exposure to the context influences conditioned fear through distinct mechanisms depending on whether it occurs during acquisition or after it. The superiority of immediate postshock context exposure was specific to single-shock CFC; in two-shock CFC, immediate and delayed postshock context exposure had similar effects. Consistent with previous reports, we hypothesize that the effectiveness of extinction is modulated by emotional state, and procedures engendering higher postshock freezing (such as two-shock CFC) are associated with weaker immediate extinction.
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spelling pubmed-42743252016-01-01 Potent attenuation of context fear by extinction training contiguous with acquisition Bernier, Brian E. Lacagnina, Anthony F. Drew, Michael R. Learn Mem Research Studies on the behavioral mechanisms underlying contextual fear conditioning (CFC) have demonstrated the importance of preshock context exposure in the formation of aversive context memories. However, there has been comparatively little investigation of the effects of context exposure immediately after the shock. Some models predict that nonreinforced context exposure at the end of the acquisition session will strongly influence the strength of conditioning and/or recruit distinct neural mechanisms relative to extinction after acquisition. Here we investigate the effects of manipulating postshock context exposure on CFC in mice. Prolonging the period of context exposure immediately following the shock caused a significant and durable reduction in conditioned fear. This immediate postshock context exposure was more effective at attenuating conditioned fear than was an equivalent amount of context exposure a day or more after acquisition. The results suggest that nonreinforced exposure to the context influences conditioned fear through distinct mechanisms depending on whether it occurs during acquisition or after it. The superiority of immediate postshock context exposure was specific to single-shock CFC; in two-shock CFC, immediate and delayed postshock context exposure had similar effects. Consistent with previous reports, we hypothesize that the effectiveness of extinction is modulated by emotional state, and procedures engendering higher postshock freezing (such as two-shock CFC) are associated with weaker immediate extinction. Cold Spring Harbor Laboratory Press 2015-01 /pmc/articles/PMC4274325/ /pubmed/25512575 http://dx.doi.org/10.1101/lm.036673.114 Text en © 2014 Bernier et al.; Published by Cold Spring Harbor Laboratory Press http://creativecommons.org/licenses/by-nc/4.0/ This article is distributed exclusively by Cold Spring Harbor Laboratory Press for the first 12 months after the full-issue publication date (see http://learnmem.cshlp.org/site/misc/terms.xhtml). After 12 months, it is available under a Creative Commons License (Attribution-NonCommercial 4.0 International), as described at http://creativecommons.org/licenses/by-nc/4.0/.
spellingShingle Research
Bernier, Brian E.
Lacagnina, Anthony F.
Drew, Michael R.
Potent attenuation of context fear by extinction training contiguous with acquisition
title Potent attenuation of context fear by extinction training contiguous with acquisition
title_full Potent attenuation of context fear by extinction training contiguous with acquisition
title_fullStr Potent attenuation of context fear by extinction training contiguous with acquisition
title_full_unstemmed Potent attenuation of context fear by extinction training contiguous with acquisition
title_short Potent attenuation of context fear by extinction training contiguous with acquisition
title_sort potent attenuation of context fear by extinction training contiguous with acquisition
topic Research
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4274325/
https://www.ncbi.nlm.nih.gov/pubmed/25512575
http://dx.doi.org/10.1101/lm.036673.114
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