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 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 (MAP50) 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 MAP50, 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.
Main Authors: | , , , |
---|---|
Format: | Digital revista |
Language: | English |
Published: |
Associação Brasileira de Divulgação Científica
2015
|
Online Access: | http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2015000200128 |
Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
id |
oai:scielo:S0100-879X2015000200128 |
---|---|
record_format |
ojs |
spelling |
oai:scielo:S0100-879X20150002001282019-03-19Neuropeptides in the posterodorsal medial amygdala modulate central cardiovascular reflex responses in awake male ratsQuagliotto,E.Casali,K.R.Dal Lago,P.Rasia-Filho,A.A. Baroreceptor and chemoreceptor reflexes Power spectral analysis Symbolic analysis Oxytocin Somatostatin Angiotensin II 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 (MAP50) 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 MAP50, 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.info:eu-repo/semantics/openAccessAssociação Brasileira de Divulgação CientíficaBrazilian Journal of Medical and Biological Research v.48 n.2 20152015-02-01info:eu-repo/semantics/articletext/htmlhttp://old.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2015000200128en10.1590/1414-431x20144095 |
institution |
SCIELO |
collection |
OJS |
country |
Brasil |
countrycode |
BR |
component |
Revista |
access |
En linea |
databasecode |
rev-scielo-br |
tag |
revista |
region |
America del Sur |
libraryname |
SciELO |
language |
English |
format |
Digital |
author |
Quagliotto,E. Casali,K.R. Dal Lago,P. Rasia-Filho,A.A. |
spellingShingle |
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 |
author_facet |
Quagliotto,E. Casali,K.R. Dal Lago,P. Rasia-Filho,A.A. |
author_sort |
Quagliotto,E. |
title |
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_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_sort |
neuropeptides in the posterodorsal medial amygdala modulate central cardiovascular reflex responses in awake male rats |
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 (MAP50) 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 MAP50, 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. |
publisher |
Associação Brasileira de Divulgação Científica |
publishDate |
2015 |
url |
http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2015000200128 |
work_keys_str_mv |
AT quagliottoe neuropeptidesintheposterodorsalmedialamygdalamodulatecentralcardiovascularreflexresponsesinawakemalerats AT casalikr neuropeptidesintheposterodorsalmedialamygdalamodulatecentralcardiovascularreflexresponsesinawakemalerats AT dallagop neuropeptidesintheposterodorsalmedialamygdalamodulatecentralcardiovascularreflexresponsesinawakemalerats AT rasiafilhoaa neuropeptidesintheposterodorsalmedialamygdalamodulatecentralcardiovascularreflexresponsesinawakemalerats |
_version_ |
1756391475692699648 |