Autonomic processing of the cardiovascular reflexes in the nucleus tractus solitarii

Autonomic processing of the cardiovascular reflexes in the nucleus tractus solitarii

Author Machado, B. H. Google Scholar
Mauad, H. Google Scholar
Chianca, D. A. Google Scholar
Haibara, A. S. Google Scholar
Colombari, Eduardo Autor UNIFESP Google Scholar
Universidade Federal de São Paulo (UNIFESP)
Abstract The nucleus tractus solitarii (NTS) receives afferent projections from the arterial baroreceptors, carotid chemoreceptors and cardiopulmonary receptors and as a function of this information produces autonomic adjustments in order to maintain arterial blood pressure within a narrow range of variation. The activation of each of these cardiovascular afferents produces a specific autonomic response by the excitation of neuronal projections from the NTS to the ventrolateral areas of the medulla (nucleus ambiguus, caudal and rostral ventrolateral medulla). The neurotransmitters at the NTS level as well as the excitatory amino acid (EAA) receptors involved in the processing of the autonomic responses in the NTS, although extensively studied, remain to be completely elucidated, In the present review we discuss the role of the EAA L-glutamate and its different receptor subtypes in the processing of the cardiovascular reflexes in the NTS. The data presented in this review related to the neurotransmission in the NTS are based on experimental evidence obtained in our laboratory in unanesthetized rats. The two major conclusions of the present review are that a) the excitation of the cardiovagal component by cardiovascular reflex activation (chemo- and Bezold-Jarisch reflexes) or by L-glutamate microinjection into the NTS is mediated by N-methyl-D-aspartate (NMDA) receptors, and b) the sympatho-excitatory component of the chemoreflex and the presser response to L-glutamate microinjected into the NTS are not affected by an NMDA receptor antagonist, suggesting that the sympatho-excitatory component of these responses is mediated by non-NMDA receptors.
Keywords L-glutamate
excitatory amino acid receptors
NMDA receptors
Bezold-Jarisch reflex
kynureic acid
Language English
Date 1997-04-01
Published in Brazilian Journal Of Medical And Biological Research. Sao Paulo: Assoc Bras Divulg Cientifica, v. 30, n. 4, p. 533-543, 1997.
ISSN 0100-879X (Sherpa/Romeo, impact factor)
Publisher Assoc Bras Divulg Cientifica
Extent 533-543
Access rights Open access Open Access
Type Article
Web of Science ID WOS:A1997WT02000015
SciELO ID S0100-879X1997000400015 (statistics in SciELO)

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