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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

INTERMITTENT ACTIVATION OF PERIPHERAL CHEMORECEPTORS IN AWAKE RATS INDUCES Fos EXPRESSION IN ROSTRAL VENTROLATERAL MEDULLA-PROJECTING NEURONS IN THE PARAVENTRICULAR NUCLEUS OF THE HYPOTHALAMUS

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Author(s):
Cruz, J. C. [1] ; Bonagamba, L. G. H. [1] ; Machado, B. H. [1] ; Biancardi, V. C. [2] ; Stern, J. E. [2]
Total Authors: 5
Affiliation:
[1] Univ Sao Paulo, Sch Med, Dept Physiol, BR-14049900 Ribeirao Preto, SP - Brazil
[2] Med Coll Georgia, Dept Physiol, Augusta, GA 30912 - USA
Total Affiliations: 2
Document type: Journal article
Source: Neuroscience; v. 157, n. 2, p. 463-472, NOV 19 2008.
Web of Science Citations: 30
Abstract

Despite the well-established sympathoexcitation evoked by chemoreflex activation, the specific sub-regions of the CNS underlying such sympathetic responses remain to be fully characterized. In the present study we examined the effects of intermittent chemoreflex activation in awake rats on Fos-immunoreactivity (Fos-ir) in various subnuclei of the paraventricular nucleus of the hypothalamus (PVN), as well as in identified neurosecretory preautonomic PVN neurons. In response to intermittent chemoreflex activation, a significant increase in the number of Fos-ir cells was found in autonomic-related PVN subnuclei, including the posterior parvocellular, ventromedial parvocellular and dorsal-cap, but not in the neurosecretory magnocellular-containing lateral magnocellular subnucleus. No changes in Fos-ir following chemoreflex activation were observed in the anterior PVN subnucleus. Experiments combining Fos immunohistochemistry and neuronal tract tracing techniques showed a significant increase in Fos-ir in rostral ventrolateral medulla (RVLM)-projecting (PVN-RVLM), but not in nucleus of solitarii tract (NTS)-projecting PVN neurons. In summary, our results support the involvement of the PVN in the central neuronal circuitry activated in response to chemoreflex activation, and indicate that PVN-RVLM neurons constitute a neuronal substrate contributing to the sympathoexcitatory component of the chemoreflex. Published by Elsevier Ltd on behalf of IBRO. (AU)

FAPESP's process: 04/03285-7 - Central mechanisms involved in the sympathoexcitation in response to hypoxia
Grantee:Benedito Honorio Machado
Support type: Research Projects - Thematic Grants