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Frequency-specific stimulations induce reconsolidation of long-term potentiation in freely moving rats

BACKGROUND: When consolidated memories are retrieved, they become labile and a new protein synthesis-dependent reconsolidation process is required to restabilize these memories. So far, most studies conducted on reconsolidation rely on the analyses of animal behavior, leaving the synaptic mechanisms...

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Autores principales: Okubo-Suzuki, Reiko, Saitoh, Yoshito, Shehata, Mohammad, Zhao, Qi, Enomoto, Hiroshi, Inokuchi, Kaoru
Formato: Online Artículo Texto
Lenguaje:English
Publicado: BioMed Central 2016
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4807568/
https://www.ncbi.nlm.nih.gov/pubmed/27012529
http://dx.doi.org/10.1186/s13041-016-0216-4
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author Okubo-Suzuki, Reiko
Saitoh, Yoshito
Shehata, Mohammad
Zhao, Qi
Enomoto, Hiroshi
Inokuchi, Kaoru
author_facet Okubo-Suzuki, Reiko
Saitoh, Yoshito
Shehata, Mohammad
Zhao, Qi
Enomoto, Hiroshi
Inokuchi, Kaoru
author_sort Okubo-Suzuki, Reiko
collection PubMed
description BACKGROUND: When consolidated memories are retrieved, they become labile and a new protein synthesis-dependent reconsolidation process is required to restabilize these memories. So far, most studies conducted on reconsolidation rely on the analyses of animal behavior, leaving the synaptic mechanisms that underlie reconsolidation largely unclear. Here, we examined whether the reconsolidation process occurs in hippocampal long term potentiation (LTP), as a synaptic model that is correlated with long term memories (LTM). RESULTS: We employed LTP system in the dentate gyrus of freely moving rats that lasts for weeks simulating LTM. LTP was induced by high frequency stimulation at 400 Hz (HFS400), and as a reactivation stimulation, we tested a low frequency stimulation at 0.1 Hz (LFS0.1), a theta stimulation at 8 Hz (TS8), or HFS400. Unlike HFS400 reactivation, both LFS0.1 and TS8 induced a reconsolidation-like phenomenon and rendered the LTP labile to protein synthesis inhibition by anisomycin. Without reactivation, LTP remained unaffected by protein synthesis inhibition. In addition, the TS8-induced LTP reconsolidation was NMDAR dependent. CONCLUSION: Our results indicate that, as with behavioral LTM, there are boundary conditions for LTP reconsolidation where only a certain range of frequency stimulations as reactivation can destabilize the consolidated LTP. This LTP reconsolidation system will be useful for future elucidation of the synaptic reconsolidation mechanism.
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spelling pubmed-48075682016-03-25 Frequency-specific stimulations induce reconsolidation of long-term potentiation in freely moving rats Okubo-Suzuki, Reiko Saitoh, Yoshito Shehata, Mohammad Zhao, Qi Enomoto, Hiroshi Inokuchi, Kaoru Mol Brain Research BACKGROUND: When consolidated memories are retrieved, they become labile and a new protein synthesis-dependent reconsolidation process is required to restabilize these memories. So far, most studies conducted on reconsolidation rely on the analyses of animal behavior, leaving the synaptic mechanisms that underlie reconsolidation largely unclear. Here, we examined whether the reconsolidation process occurs in hippocampal long term potentiation (LTP), as a synaptic model that is correlated with long term memories (LTM). RESULTS: We employed LTP system in the dentate gyrus of freely moving rats that lasts for weeks simulating LTM. LTP was induced by high frequency stimulation at 400 Hz (HFS400), and as a reactivation stimulation, we tested a low frequency stimulation at 0.1 Hz (LFS0.1), a theta stimulation at 8 Hz (TS8), or HFS400. Unlike HFS400 reactivation, both LFS0.1 and TS8 induced a reconsolidation-like phenomenon and rendered the LTP labile to protein synthesis inhibition by anisomycin. Without reactivation, LTP remained unaffected by protein synthesis inhibition. In addition, the TS8-induced LTP reconsolidation was NMDAR dependent. CONCLUSION: Our results indicate that, as with behavioral LTM, there are boundary conditions for LTP reconsolidation where only a certain range of frequency stimulations as reactivation can destabilize the consolidated LTP. This LTP reconsolidation system will be useful for future elucidation of the synaptic reconsolidation mechanism. BioMed Central 2016-03-25 /pmc/articles/PMC4807568/ /pubmed/27012529 http://dx.doi.org/10.1186/s13041-016-0216-4 Text en © Okubo-Suzuki et al. 2016 Open AccessThis article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.
spellingShingle Research
Okubo-Suzuki, Reiko
Saitoh, Yoshito
Shehata, Mohammad
Zhao, Qi
Enomoto, Hiroshi
Inokuchi, Kaoru
Frequency-specific stimulations induce reconsolidation of long-term potentiation in freely moving rats
title Frequency-specific stimulations induce reconsolidation of long-term potentiation in freely moving rats
title_full Frequency-specific stimulations induce reconsolidation of long-term potentiation in freely moving rats
title_fullStr Frequency-specific stimulations induce reconsolidation of long-term potentiation in freely moving rats
title_full_unstemmed Frequency-specific stimulations induce reconsolidation of long-term potentiation in freely moving rats
title_short Frequency-specific stimulations induce reconsolidation of long-term potentiation in freely moving rats
title_sort frequency-specific stimulations induce reconsolidation of long-term potentiation in freely moving rats
topic Research
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4807568/
https://www.ncbi.nlm.nih.gov/pubmed/27012529
http://dx.doi.org/10.1186/s13041-016-0216-4
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