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Fear expression is suppressed by tyrosine administration

Animal studies have demonstrated that catecholamines regulate several aspects of fear conditioning. In humans, however, pharmacological manipulations of the catecholaminergic system have been scarce, and their primary focus has been to interfering with catecholaminergic activity after fear acquisiti...

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Autores principales: Soranzo, Alessandro, Aquili, Luca
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Nature Publishing Group UK 2019
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6831598/
https://www.ncbi.nlm.nih.gov/pubmed/31690824
http://dx.doi.org/10.1038/s41598-019-52610-x
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author Soranzo, Alessandro
Aquili, Luca
author_facet Soranzo, Alessandro
Aquili, Luca
author_sort Soranzo, Alessandro
collection PubMed
description Animal studies have demonstrated that catecholamines regulate several aspects of fear conditioning. In humans, however, pharmacological manipulations of the catecholaminergic system have been scarce, and their primary focus has been to interfering with catecholaminergic activity after fear acquisition or expression had taken place, using L-Dopa, primarily, as catecholaminergic precursor. Here, we sought to determine if putative increases in presynaptic dopamine and norepinephrine by tyrosine administered before conditioning could affect fear expression. Electrodermal activity (EDA) of 46 healthy participants (24 placebo, 22 tyrosine) was measured in an instructed fear task. Results showed that tyrosine abolished fear expression compared to placebo. Importantly, tyrosine did not affect EDA responses to the aversive stimulus (UCS) or alter participants’ mood. Therefore, the effect of tyrosine on fear expression cannot be attributed to these factors. Taken together, these findings provide evidence that the catecholaminergic system influences fear expression in humans.
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spelling pubmed-68315982019-11-13 Fear expression is suppressed by tyrosine administration Soranzo, Alessandro Aquili, Luca Sci Rep Article Animal studies have demonstrated that catecholamines regulate several aspects of fear conditioning. In humans, however, pharmacological manipulations of the catecholaminergic system have been scarce, and their primary focus has been to interfering with catecholaminergic activity after fear acquisition or expression had taken place, using L-Dopa, primarily, as catecholaminergic precursor. Here, we sought to determine if putative increases in presynaptic dopamine and norepinephrine by tyrosine administered before conditioning could affect fear expression. Electrodermal activity (EDA) of 46 healthy participants (24 placebo, 22 tyrosine) was measured in an instructed fear task. Results showed that tyrosine abolished fear expression compared to placebo. Importantly, tyrosine did not affect EDA responses to the aversive stimulus (UCS) or alter participants’ mood. Therefore, the effect of tyrosine on fear expression cannot be attributed to these factors. Taken together, these findings provide evidence that the catecholaminergic system influences fear expression in humans. Nature Publishing Group UK 2019-11-05 /pmc/articles/PMC6831598/ /pubmed/31690824 http://dx.doi.org/10.1038/s41598-019-52610-x Text en © The Author(s) 2019 Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as 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 images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/.
spellingShingle Article
Soranzo, Alessandro
Aquili, Luca
Fear expression is suppressed by tyrosine administration
title Fear expression is suppressed by tyrosine administration
title_full Fear expression is suppressed by tyrosine administration
title_fullStr Fear expression is suppressed by tyrosine administration
title_full_unstemmed Fear expression is suppressed by tyrosine administration
title_short Fear expression is suppressed by tyrosine administration
title_sort fear expression is suppressed by tyrosine administration
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6831598/
https://www.ncbi.nlm.nih.gov/pubmed/31690824
http://dx.doi.org/10.1038/s41598-019-52610-x
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