Fos expression in the NTS in response to peripheral chemoreflex activation in awake rats
Contribuinte(s) |
UNIVERSIDADE DE SÃO PAULO |
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Data(s) |
19/10/2012
19/10/2012
2010
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Resumo |
Chemoreflex afferent fibers terminate in the nucleus tractus solitarii (NTS), but the specific location of the NTS neurons excited by peripheral chemoreflex activation remains to be characterized. Here, the topographic distribution of chemoreflex sensitive cells at the commissural NTS was evaluated. To reach this goal, Fos-immunoreactive neurons (Fos-ir) were accounted in rostro-caudal levels of the intermediate and caudal commissural NTS, after intermittent chemoreflex activation with intravenous injection of potassium cyanide [KCN (80 mu g/kg) or saline (0.9%, vehicle), one injection every 3 min during 30 min]. In response to intermittent intravenous injections of KCN, a significant increase in the number of Fos-ir neurons was observed specifically in the lateral intermediate commissural NTS [(LI)NTS (82 +/- 9 vs. 174 +/- 16, cell number mean per section)] and lateral caudal commissural NTS [(LI)NTS (71 +/- 9 vs. 199 +/- 18, cell number mean per section)]. To evaluate the influence of baroreceptor-mediated inputs following the increase in blood pressure during intermittent chemoreflex activation, we performed an intermittent activation of the arterial baroreflex by intravenous injection of phenylephrine [1.5 mu g/kg iv (one injection every 3 min during 30 min)]. This procedure induced no change in Fos-ir in (LI)NTS (64 +/- 6 vs. 62 +/- 12, cell number mean per section) or (LC)NTS (56 +/- 15 vs. 77 +/- 12, cell number mean per section). These data support the involvement of the commissural NTS in the processing of peripheral chemoreflex, and provide a detailed characterization of the topographical distribution of activated neurons within this brain region. (C) 2009 Elsevier B.V. All rights reserved. FAPESP[2004/03285-7] CNPQ[522150/95-0] CAPES NIH[HL68725] |
Identificador |
AUTONOMIC NEUROSCIENCE-BASIC & CLINICAL, v.152, n.1/Fev, p.27-34, 2010 1566-0702 http://producao.usp.br/handle/BDPI/24407 10.1016/j.autneu.2009.08.016 |
Idioma(s) |
eng |
Publicador |
ELSEVIER SCIENCE BV |
Relação |
Autonomic Neuroscience-basic & Clinical |
Direitos |
restrictedAccess Copyright ELSEVIER SCIENCE BV |
Palavras-Chave | #Chemoreflex #Baroreflex #Fos protein #Nucleus tractus solitarii #Cardiovascular regulation #ROSTRAL VENTROLATERAL MEDULLA #NUCLEUS-TRACTUS-SOLITARII #CAROTID-SINUS NERVE #BRAIN-STEM #C-FOS #HYPOXIA #NEURONS #STIMULATION #NEUROTRANSMISSION #IMMUNOREACTIVITY #Neurosciences |
Tipo |
article original article publishedVersion |