Contribution of excitatory amino acid receptors of the retrotrapezoid nucleus to the sympathetic chemoreflex in rats

Abstract

In the present study, we evaluated the role of glutamatergic mechanisms in the retrotrapezoid nucleus (RTN) in changes of splanchnic sympathetic nerve discharge (sSND) and phrenic nerve discharge

Evolution and physiology of neural oxygen sensing

“…Other regions of the VRG, including the Bötzinger complex (BötC), the rostral ventral respiratory group (rVRG), and the caudal ventral respiratory group (cVRG), are also thought to be involved in the processing of the respiratory responses to chemoreflex activation, particularly in the forced inspiration and expiration pattern observed following carotid body activation (Guyenet, 2000; Abdala et al, 2009a; Mandel and Schreihofer, 2009; Zoccal et al, 2009b; Zoccal and Machado, 2011; Moraes et al, 2012b). The Retrotrapezoid nucleus (RTN) and the Parafacial Respiratory Group (RTN/pFRG), also receive chemoreflex related input (Figure 4) and are involved in the expiratory and sympatho-excitatory components of the response to hypoxia (Takakura et al, 2006; Abdala et al, 2009a; Abbott et al, 2011; Pagliardini et al, 2011; Takakura and Moreira, 2011; Damasceno et al, 2014a,b). In addition, there is growing evidence that NTS projections to pontine nuclei, especially to the parabrachial nucleus (PBN) and the Kölliker fuse (KF), also play an important role in the respiratory repercussions of chemoreflex activation (Abdala et al, 2009b; Costa-Silva et al, 2010; Song et al, 2011).…”

Mecanismos purinérgicos no bulbo ventrolateral rostral modulam respostas cardiovasculares e respiratórias promovidas pela ativação dos quimiorreceptores centrais e periféricos.

“…In vitro, loose-patch recordings from RTN neurons show that P2 receptor blockers decreased responsiveness to both 10% and 15% CO 2 also by 30%. In the slice, the contribution of purinergic signalling to RTN chemoreception did not increase with temperature (22)(23)(24)(25)(26)(27)(28)(29)(30)(31)(32)(33)(34)(35) • C) and was retained in low extracellular Ca 2+ medium. Conversely, the gap junction blockers carbenoxolone and cobalt decreased neuronal CO 2 /H + sensitivity by an amount similar to P2 receptor antagonists.…”

“…34 The injection center was 250 µm below the facial motor nucleus and 200 µm rostral to the caudal end of this nucleus ( Figure 1B). 10,35 Bilateral injections of PPADS (100 µmol/L, 50 nL) into the RVLM did not change baseline mean arterial pressure (MAP; 119±5 mm Hg compared with saline 121±6 mm Hg), splanchnic SNA (sSNA; 101±11% of control), or phrenic nerve activity (PNA) activity (97±4% of control value). However, PPADS treatment strongly inhibited cardiorespiratory responses to peripheral chemoreceptor acti vation.…”

Interação entre o grupamento parafacial/núcleo retrotrapezóide e a região de kölliker-fuse na modulação do padrão respiratório.

“…3) colocados em um aparelho estereotáxico (modelo Kopf 1760); 4) localização e exposição do nervo vago via posição dorsolateral (MOREIRA et al., 2006;PAGLIARDINI et al, 2011;TAKAKURA et al., 2006TAKAKURA et al., , 2007TAKAKURA et al., , 2008TAKAKURA et al., , 2011TAKAKURA et al., , 2012; 5) Todos os animais foram vagotomizados bilateralmente a fim de prevenir uma influência da ventilação na atividade do nervo frênico.…”

“…A musculatura da laringe esta envolvida em diversas funções fisiológicas como o funcionamento adequado das cordas vocais, na regulação da abertura da glote, no controle da resistência das vias aéreas e em reflexos protetores das vias aéreas (HORNER, 2013 (TAKAKURA et al, 2006;, mas uma região integradora de respostas autônomas (MOREIRA et al, 2007a;TAKAKURA et al, 2011; TAKAKURA; MOREIRA, 2011) e respiratórias (ABBOTT et al, 2011(ABBOTT et al, , 2013MOREIRA et al, 2007b;presentes resultados).…”