GABAergic pump cells of solitary tract nucleus innervate retrotrapezoid nucleus chemoreceptors

GABAergic pump cells of solitary tract nucleus innervate retrotrapezoid nucleus chemoreceptors

Author Takakura, Ana C. Autor UNIFESP Google Scholar
Moreira, Thiago S. Autor UNIFESP Google Scholar
West, Gavin H. Google Scholar
Gwilt, Justin M. Google Scholar
Colombari, Eduardo Autor UNIFESP Google Scholar
Stornetta, Ruth L. Google Scholar
Guyenet, Patrice G. Google Scholar
Institution Univ Virginia Hlth Syst
Universidade Federal de São Paulo (UNIFESP)
Abstract GABAergic pump cells of solitary tract nucleus innervate retrotrapezoid nucleus chemoreceptors. J Neurophysiol 98: 374 - 381, 2007. First published April 25, 2007; doi: 10.1152/ jn. 00322.2007. the retrotrapezoid nucleus (RTN) contains central respiratory chemoreceptors that are inhibited by activation of slowly adapting pulmonary stretch receptors (SARs). Here we examine whether RTN inhibition by lung inflation could be mediated by a direct projection from SAR second- order neurons (pump cells). Pump cells ( n = 56 neurons, 13 rats) were recorded in the nucleus of solitary tract (NTS) of halothane- anesthetized rats with intact vagus nerves. Pump cells had discharges that coincided with lung inflation as monitored by the tracheal pressure. Their activity increased when end- expiratory pressure was raised and stopped instantly when ventilation was interrupted in expiration. Many pump cells could be antidromically activated from RTN (12/36). Nine of those were labeled with biotinamide. of these nine cells, eight contained glutamic acid decarboxylase 67 (GAD67) mRNA and seven were found to reside in the lower half of the interstitial subnucleus of NTS (iNTS). Using the retrograde tracer cholera toxin-B, we confirmed that neurons located in or close to iNTS innervate RTN (two rats). Many such neurons contained GAD67 mRNA and a few contained glycine transporter2 (GLYT2) mRNA. Anterograde tract tracing with biotinylated dextranamide (four rats) applied to iNTS also confirmed that this region innervates RTN by a predominantly GABAergic projection. This work confirms that many rat NTS pump cells are located in and around the interstitial subnucleus at area postrema level. We demonstrate that a GABAergic subset of these pump cells innervates the RTN region. We conclude that these inhibitory neurons probably contact RTN chemoreceptors and mediate their inhibition by lung inflation.
Language English
Date 2007-07-01
Published in Journal of Neurophysiology. Bethesda: Amer Physiological Soc, v. 98, n. 1, p. 374-381, 2007.
ISSN 0022-3077 (Sherpa/Romeo, impact factor)
Publisher Amer Physiological Soc
Extent 374-381
Origin http://dx.doi.org/10.1152/jn.00322.2007
Access rights Open access Open Access
Type Article
Web of Science ID WOS:000247938400036
URI http://repositorio.unifesp.br/handle/11600/29835

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