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Impaired fear extinction in serotonin transporter knockout rats is associated with increased 5‐hydroxymethylcytosine in the amygdala

AIMS: One potential risk factor for posttraumatic stress disorder (PTSD) involves the low activity (short; s) allelic variant of the serotonin transporter‐linked polymorphic region (5‐HTTLPR), possibly due to reduced prefrontal control over the amygdala. Evidence shows that DNA methylation/demethyla...

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Autores principales: Shan, Ling, Guo, Hang‐Yuan, van den Heuvel, Corina N. A. M., van Heerikhuize, Joop, Homberg, Judith R.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: John Wiley and Sons Inc. 2018
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6120487/
https://www.ncbi.nlm.nih.gov/pubmed/29427306
http://dx.doi.org/10.1111/cns.12822
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author Shan, Ling
Guo, Hang‐Yuan
van den Heuvel, Corina N. A. M.
van Heerikhuize, Joop
Homberg, Judith R.
author_facet Shan, Ling
Guo, Hang‐Yuan
van den Heuvel, Corina N. A. M.
van Heerikhuize, Joop
Homberg, Judith R.
author_sort Shan, Ling
collection PubMed
description AIMS: One potential risk factor for posttraumatic stress disorder (PTSD) involves the low activity (short; s) allelic variant of the serotonin transporter‐linked polymorphic region (5‐HTTLPR), possibly due to reduced prefrontal control over the amygdala. Evidence shows that DNA methylation/demethylation is crucial for fear extinction in these brain areas and is associated with neuronal activation marker c‐Fos expression. We hypothesized that impaired fear extinction in serotonin transporter knockout (5‐HTT (−/−)) rats is related to changes in DNA (de) methylation and c‐Fos expression in the prefrontal cortex (PFC) and/or amygdala. METHODS: 5‐HTT (−/−) and 5‐HTT (+/+) rats were subjected to fear extinction. 2 hours after the extinction session, the overall levels of DNA methylation (5‐mC), demethylation (5‐hmC), and c‐Fos in fear extinction and nonfear extinction rats were measured by immunohistochemistry. RESULTS: 5‐HTT (−/−) rats displayed decreased fear extinction. This was associated with reduced c‐Fos activity in the infralimbic PFC. In the central nucleus of the amygdala, c‐Fos immunoreactivity was increased in the fear extinction group compared to the no‐fear extinction group, regardless of genotype. 5‐hmC levels were unaltered in the PFC, but reduced in the amygdala of nonextinction 5‐HTT (−/−) rats compared to nonextinction wild‐type rats, which caught up to wild‐type levels during fear extinction. 5‐mC levels were stable in central amygdala in both wild‐type and 5‐HTT (−/−) extinction rats. Finally, c‐Fos and 5‐mC levels were correlated with the prelimbic PFC, but not amygdala. CONCLUSIONS: In the amygdala, DNA demethylation, independent from c‐Fos activation, may contribute to individual differences in risk for PTSD, as conferred by the 5‐HTTLPR s‐allele.
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spelling pubmed-61204872018-09-05 Impaired fear extinction in serotonin transporter knockout rats is associated with increased 5‐hydroxymethylcytosine in the amygdala Shan, Ling Guo, Hang‐Yuan van den Heuvel, Corina N. A. M. van Heerikhuize, Joop Homberg, Judith R. CNS Neurosci Ther Original Articles AIMS: One potential risk factor for posttraumatic stress disorder (PTSD) involves the low activity (short; s) allelic variant of the serotonin transporter‐linked polymorphic region (5‐HTTLPR), possibly due to reduced prefrontal control over the amygdala. Evidence shows that DNA methylation/demethylation is crucial for fear extinction in these brain areas and is associated with neuronal activation marker c‐Fos expression. We hypothesized that impaired fear extinction in serotonin transporter knockout (5‐HTT (−/−)) rats is related to changes in DNA (de) methylation and c‐Fos expression in the prefrontal cortex (PFC) and/or amygdala. METHODS: 5‐HTT (−/−) and 5‐HTT (+/+) rats were subjected to fear extinction. 2 hours after the extinction session, the overall levels of DNA methylation (5‐mC), demethylation (5‐hmC), and c‐Fos in fear extinction and nonfear extinction rats were measured by immunohistochemistry. RESULTS: 5‐HTT (−/−) rats displayed decreased fear extinction. This was associated with reduced c‐Fos activity in the infralimbic PFC. In the central nucleus of the amygdala, c‐Fos immunoreactivity was increased in the fear extinction group compared to the no‐fear extinction group, regardless of genotype. 5‐hmC levels were unaltered in the PFC, but reduced in the amygdala of nonextinction 5‐HTT (−/−) rats compared to nonextinction wild‐type rats, which caught up to wild‐type levels during fear extinction. 5‐mC levels were stable in central amygdala in both wild‐type and 5‐HTT (−/−) extinction rats. Finally, c‐Fos and 5‐mC levels were correlated with the prelimbic PFC, but not amygdala. CONCLUSIONS: In the amygdala, DNA demethylation, independent from c‐Fos activation, may contribute to individual differences in risk for PTSD, as conferred by the 5‐HTTLPR s‐allele. John Wiley and Sons Inc. 2018-02-09 /pmc/articles/PMC6120487/ /pubmed/29427306 http://dx.doi.org/10.1111/cns.12822 Text en © 2018 The Authors. CNS Neuroscience & Therapeutics Published by John Wiley & Sons Ltd. This is an open access article under the terms of the http://creativecommons.org/licenses/by-nc/4.0/ License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited and is not used for commercial purposes.
spellingShingle Original Articles
Shan, Ling
Guo, Hang‐Yuan
van den Heuvel, Corina N. A. M.
van Heerikhuize, Joop
Homberg, Judith R.
Impaired fear extinction in serotonin transporter knockout rats is associated with increased 5‐hydroxymethylcytosine in the amygdala
title Impaired fear extinction in serotonin transporter knockout rats is associated with increased 5‐hydroxymethylcytosine in the amygdala
title_full Impaired fear extinction in serotonin transporter knockout rats is associated with increased 5‐hydroxymethylcytosine in the amygdala
title_fullStr Impaired fear extinction in serotonin transporter knockout rats is associated with increased 5‐hydroxymethylcytosine in the amygdala
title_full_unstemmed Impaired fear extinction in serotonin transporter knockout rats is associated with increased 5‐hydroxymethylcytosine in the amygdala
title_short Impaired fear extinction in serotonin transporter knockout rats is associated with increased 5‐hydroxymethylcytosine in the amygdala
title_sort impaired fear extinction in serotonin transporter knockout rats is associated with increased 5‐hydroxymethylcytosine in the amygdala
topic Original Articles
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6120487/
https://www.ncbi.nlm.nih.gov/pubmed/29427306
http://dx.doi.org/10.1111/cns.12822
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