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Neuropeptides in the posterodorsal medial amygdala modulate central cardiovascular reflex responses in awake male rats

The rat posterodorsal medial amygdala (MePD) links emotionally charged sensory stimuli to social behavior, and is part of the supramedullary control of the cardiovascular system. We studied the effects of microinjections of neuroactive peptides markedly found in the MePD, namely oxytocin (OT, 10 ng...

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Autores principales: Quagliotto, E., Casali, K.R., Dal Lago, P., Rasia-Filho, A.A.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Associação Brasileira de Divulgação Científica 2014
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4321218/
https://www.ncbi.nlm.nih.gov/pubmed/25424367
http://dx.doi.org/10.1590/1414-431X20144095
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author Quagliotto, E.
Casali, K.R.
Dal Lago, P.
Rasia-Filho, A.A.
author_facet Quagliotto, E.
Casali, K.R.
Dal Lago, P.
Rasia-Filho, A.A.
author_sort Quagliotto, E.
collection PubMed
description The rat posterodorsal medial amygdala (MePD) links emotionally charged sensory stimuli to social behavior, and is part of the supramedullary control of the cardiovascular system. We studied the effects of microinjections of neuroactive peptides markedly found in the MePD, namely oxytocin (OT, 10 ng and 25 pg; n=6/group), somatostatin (SST, 1 and 0.05 μM; n=8 and 5, respectively), and angiotensin II (Ang II, 50 pmol and 50 fmol; n=7/group), on basal cardiovascular activity and on baroreflex- and chemoreflex-mediated responses in awake adult male rats. Power spectral and symbolic analyses were applied to pulse interval and systolic arterial pressure series to identify centrally mediated sympathetic/parasympathetic components in the heart rate variability (HRV) and arterial pressure variability (APV). No microinjected substance affected basal parameters. On the other hand, compared with the control data (saline, 0.3 µL; n=7), OT (10 ng) decreased mean AP (MAP(50)) after baroreflex stimulation and increased both the mean AP response after chemoreflex activation and the high-frequency component of the HRV. OT (25 pg) increased overall HRV but did not affect any parameter of the symbolic analysis. SST (1 μM) decreased MAP(50), and SST (0.05 μM) enhanced the sympathovagal cardiac index. Both doses of SST increased HRV and its low-frequency component. Ang II (50 pmol) increased HRV and reduced the two unlike variations pattern of the symbolic analysis (P<0.05 in all cases). These results demonstrate neuropeptidergic actions in the MePD for both the increase in the range of the cardiovascular reflex responses and the involvement of the central sympathetic and parasympathetic systems on HRV and APV.
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spelling pubmed-43212182015-02-24 Neuropeptides in the posterodorsal medial amygdala modulate central cardiovascular reflex responses in awake male rats Quagliotto, E. Casali, K.R. Dal Lago, P. Rasia-Filho, A.A. Braz J Med Biol Res Biomedical Sciences The rat posterodorsal medial amygdala (MePD) links emotionally charged sensory stimuli to social behavior, and is part of the supramedullary control of the cardiovascular system. We studied the effects of microinjections of neuroactive peptides markedly found in the MePD, namely oxytocin (OT, 10 ng and 25 pg; n=6/group), somatostatin (SST, 1 and 0.05 μM; n=8 and 5, respectively), and angiotensin II (Ang II, 50 pmol and 50 fmol; n=7/group), on basal cardiovascular activity and on baroreflex- and chemoreflex-mediated responses in awake adult male rats. Power spectral and symbolic analyses were applied to pulse interval and systolic arterial pressure series to identify centrally mediated sympathetic/parasympathetic components in the heart rate variability (HRV) and arterial pressure variability (APV). No microinjected substance affected basal parameters. On the other hand, compared with the control data (saline, 0.3 µL; n=7), OT (10 ng) decreased mean AP (MAP(50)) after baroreflex stimulation and increased both the mean AP response after chemoreflex activation and the high-frequency component of the HRV. OT (25 pg) increased overall HRV but did not affect any parameter of the symbolic analysis. SST (1 μM) decreased MAP(50), and SST (0.05 μM) enhanced the sympathovagal cardiac index. Both doses of SST increased HRV and its low-frequency component. Ang II (50 pmol) increased HRV and reduced the two unlike variations pattern of the symbolic analysis (P<0.05 in all cases). These results demonstrate neuropeptidergic actions in the MePD for both the increase in the range of the cardiovascular reflex responses and the involvement of the central sympathetic and parasympathetic systems on HRV and APV. Associação Brasileira de Divulgação Científica 2014-11-21 /pmc/articles/PMC4321218/ /pubmed/25424367 http://dx.doi.org/10.1590/1414-431X20144095 Text en http://creativecommons.org/licenses/by-nc/3.0/ This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License, which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.
spellingShingle Biomedical Sciences
Quagliotto, E.
Casali, K.R.
Dal Lago, P.
Rasia-Filho, A.A.
Neuropeptides in the posterodorsal medial amygdala modulate central cardiovascular reflex responses in awake male rats
title Neuropeptides in the posterodorsal medial amygdala modulate central cardiovascular reflex responses in awake male rats
title_full Neuropeptides in the posterodorsal medial amygdala modulate central cardiovascular reflex responses in awake male rats
title_fullStr Neuropeptides in the posterodorsal medial amygdala modulate central cardiovascular reflex responses in awake male rats
title_full_unstemmed Neuropeptides in the posterodorsal medial amygdala modulate central cardiovascular reflex responses in awake male rats
title_short Neuropeptides in the posterodorsal medial amygdala modulate central cardiovascular reflex responses in awake male rats
title_sort neuropeptides in the posterodorsal medial amygdala modulate central cardiovascular reflex responses in awake male rats
topic Biomedical Sciences
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4321218/
https://www.ncbi.nlm.nih.gov/pubmed/25424367
http://dx.doi.org/10.1590/1414-431X20144095
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