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The Medial Amygdala-Medullary PrRP-Synthesizing Neuron Pathway Mediates Neuroendocrine Responses to Contextual Conditioned Fear in Male Rodents

Fear responses play evolutionarily beneficial roles, although excessive fear memory can induce inappropriate fear expression observed in posttraumatic stress disorder, panic disorder, and phobia. To understand the neural machineries that underlie these disorders, it is important to clarify the neura...

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Autores principales: Yoshida, Masahide, Takayanagi, Yuki, Onaka, Tatsushi
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Endocrine Society 2014
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4207914/
https://www.ncbi.nlm.nih.gov/pubmed/24877622
http://dx.doi.org/10.1210/en.2013-1411
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author Yoshida, Masahide
Takayanagi, Yuki
Onaka, Tatsushi
author_facet Yoshida, Masahide
Takayanagi, Yuki
Onaka, Tatsushi
author_sort Yoshida, Masahide
collection PubMed
description Fear responses play evolutionarily beneficial roles, although excessive fear memory can induce inappropriate fear expression observed in posttraumatic stress disorder, panic disorder, and phobia. To understand the neural machineries that underlie these disorders, it is important to clarify the neural pathways of fear responses. Contextual conditioned fear induces freezing behavior and neuroendocrine responses. Considerable evidence indicates that the central amygdala plays an essential role in expression of freezing behavior after contextual conditioned fear. On the other hand, mechanisms of neuroendocrine responses remain to be clarified. The medial amygdala (MeA), which is activated after contextual conditioned fear, was lesioned bilaterally by infusion of N-methyl-d-aspartate after training of fear conditioning. Plasma oxytocin, ACTH, and prolactin concentrations were significantly increased after contextual conditioned fear in sham-lesioned rats. In MeA-lesioned rats, these neuroendocrine responses but not freezing behavior were significantly impaired compared with those in sham-lesioned rats. In contrast, the magnitudes of neuroendocrine responses after exposure to novel environmental stimuli were not significantly different in MeA-lesioned rats and sham-lesioned rats. Contextual conditioned fear activated prolactin-releasing peptide (PrRP)-synthesizing neurons in the medulla oblongata. In MeA-lesioned rats, the percentage of PrRP-synthesizing neurons activated after contextual conditioned fear was significantly decreased. Furthermore, neuroendocrine responses after contextual conditioned fear disappeared in PrRP-deficient mice. Our findings suggest that the MeA-medullary PrRP-synthesizing neuron pathway plays an important role in neuroendocrine responses to contextual conditioned fear.
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spelling pubmed-42079142014-11-04 The Medial Amygdala-Medullary PrRP-Synthesizing Neuron Pathway Mediates Neuroendocrine Responses to Contextual Conditioned Fear in Male Rodents Yoshida, Masahide Takayanagi, Yuki Onaka, Tatsushi Endocrinology Neuroendocrinology Fear responses play evolutionarily beneficial roles, although excessive fear memory can induce inappropriate fear expression observed in posttraumatic stress disorder, panic disorder, and phobia. To understand the neural machineries that underlie these disorders, it is important to clarify the neural pathways of fear responses. Contextual conditioned fear induces freezing behavior and neuroendocrine responses. Considerable evidence indicates that the central amygdala plays an essential role in expression of freezing behavior after contextual conditioned fear. On the other hand, mechanisms of neuroendocrine responses remain to be clarified. The medial amygdala (MeA), which is activated after contextual conditioned fear, was lesioned bilaterally by infusion of N-methyl-d-aspartate after training of fear conditioning. Plasma oxytocin, ACTH, and prolactin concentrations were significantly increased after contextual conditioned fear in sham-lesioned rats. In MeA-lesioned rats, these neuroendocrine responses but not freezing behavior were significantly impaired compared with those in sham-lesioned rats. In contrast, the magnitudes of neuroendocrine responses after exposure to novel environmental stimuli were not significantly different in MeA-lesioned rats and sham-lesioned rats. Contextual conditioned fear activated prolactin-releasing peptide (PrRP)-synthesizing neurons in the medulla oblongata. In MeA-lesioned rats, the percentage of PrRP-synthesizing neurons activated after contextual conditioned fear was significantly decreased. Furthermore, neuroendocrine responses after contextual conditioned fear disappeared in PrRP-deficient mice. Our findings suggest that the MeA-medullary PrRP-synthesizing neuron pathway plays an important role in neuroendocrine responses to contextual conditioned fear. Endocrine Society 2014-08 2014-05-30 /pmc/articles/PMC4207914/ /pubmed/24877622 http://dx.doi.org/10.1210/en.2013-1411 Text en Copyright © 2014 by the Endocrine Society This article has been published under the terms of the Creative Commons Attribution License (CC-BY (http://creativecommons.org/licenses/by/3.0/) ), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Copyright for this article is retained by the author(s). Author(s) grant(s) the Endocrine Society the exclusive right to publish the article and identify itself as the original publisher.
spellingShingle Neuroendocrinology
Yoshida, Masahide
Takayanagi, Yuki
Onaka, Tatsushi
The Medial Amygdala-Medullary PrRP-Synthesizing Neuron Pathway Mediates Neuroendocrine Responses to Contextual Conditioned Fear in Male Rodents
title The Medial Amygdala-Medullary PrRP-Synthesizing Neuron Pathway Mediates Neuroendocrine Responses to Contextual Conditioned Fear in Male Rodents
title_full The Medial Amygdala-Medullary PrRP-Synthesizing Neuron Pathway Mediates Neuroendocrine Responses to Contextual Conditioned Fear in Male Rodents
title_fullStr The Medial Amygdala-Medullary PrRP-Synthesizing Neuron Pathway Mediates Neuroendocrine Responses to Contextual Conditioned Fear in Male Rodents
title_full_unstemmed The Medial Amygdala-Medullary PrRP-Synthesizing Neuron Pathway Mediates Neuroendocrine Responses to Contextual Conditioned Fear in Male Rodents
title_short The Medial Amygdala-Medullary PrRP-Synthesizing Neuron Pathway Mediates Neuroendocrine Responses to Contextual Conditioned Fear in Male Rodents
title_sort medial amygdala-medullary prrp-synthesizing neuron pathway mediates neuroendocrine responses to contextual conditioned fear in male rodents
topic Neuroendocrinology
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4207914/
https://www.ncbi.nlm.nih.gov/pubmed/24877622
http://dx.doi.org/10.1210/en.2013-1411
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