Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
2008-5-7
pubmed:abstractText
The baroreflex control of heart rate (HR) is reduced following chronic intermittent hypoxia (CIH). Since the nucleus ambiguus (NA) plays a key role in baroreflex control of HR, we examined whether CIH remodels vagal efferent projections to cardiac ganglia. C57BL/6J mice (3-4 months of age) were exposed to either room air (RA) or CIH for 3 months. Confocal microscopy was used to examine NA axons and terminals in cardiac ganglia following Fluoro-Gold (FG) injections to label cardiac ganglia, and microinjections of tracer DiI into the left NA to anterogradely label vagal efferents. We found that: 1) Cardiac ganglia were widely distributed on the dorsal surface of the atria. Although the total number of cardiac ganglia did not differ between RA and CIH mice, the size of ganglia and the somatic area of cardiac principal neurons (PNs) were significantly decreased (P < 0.01), and the size of the PN nuclei was increased following CIH (P < 0.01). 2) NA axons entered cardiac ganglia and innervated PNs with dense basket endings in both RA and CIH mice, and the percentage of innervated PNs was similar (RA: 50 +/- 1.0%; CIH: 49 +/- 1.0%; P > 0.10). In CIH mice, however, swollen cardiac axons and terminals without close contacts to PNs were found. Furthermore, varicose endings around PNs appeared swollen and the axonal varicose area around PNs was almost doubled in size (CIH: 163.1 +/- 6.4 microm(2); RA: 88 +/- 3.9 microm(2), P < 0.01). Thus, CIH significantly altered the structure of cardiac ganglia and resulted in reorganized vagal efferent projections to cardiac ganglia. Such remodeling of cardiac ganglia and vagal efferent projections provides new insight into the effects of CIH on the brain-heart circuitry of C57BL/6J mice.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
1096-9861
pubmed:author
pubmed:copyrightInfo
(c) 2008 Wiley-Liss, Inc.
pubmed:issnType
Electronic
pubmed:day
1
pubmed:volume
509
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
103-17
pubmed:meshHeading
pubmed:year
2008
pubmed:articleTitle
Structural remodeling of nucleus ambiguus projections to cardiac ganglia following chronic intermittent hypoxia in C57BL/6J mice.
pubmed:affiliation
Biomolecular Science Center, Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, Florida 32816, USA.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, Non-U.S. Gov't, Research Support, N.I.H., Extramural