Linked Life Data

16399669

Source:http://linkedlifedata.com/resource/pubmed/id/16399669

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
2006-1-9
pubmed:abstractText
Hypercapnia evokes a strong cardiorespiratory response including gasping and a pronounced bradycardia; however, the mechanism responsible for these survival responses initiated in the brainstem is unknown. To examine the effects of hypercapnia on the central cardiorespiratory network, we used an in vitro medullary slice that allows simultaneous examination of rhythmic respiratory-related activity and inhibitory synaptic neurotransmission to cardioinhibitory vagal neurons (CVNs). Hypercapnia differentially modulated inhibitory neurotransmission to CVNs; whereas hypercapnia selectively depressed spontaneous glycinergic IPSCs in CVNs without altering respiratory-related increases in glycinergic neurotransmission, it decreased both spontaneous and inspiratory-associated GABAergic IPSCs. Because maternal smoking is the highest risk factor for sudden infant death syndrome (SIDS) and prenatal nicotine exposure is proposed to be the link between maternal smoking and SIDS, we examined the cardiorespiratory responses to hypercapnia in animals exposed to nicotine in the prenatal and perinatal period. In animals exposed to prenatal nicotine, hypercapnia evoked an exaggerated depression of GABAergic IPSCs in CVNs with no significant change in glycinergic neurotransmission. Hypercapnia altered inhibitory neurotransmission to CVNs at both presynaptic and postsynaptic sites. Although the results obtained in this study in vitro cannot be extrapolated with certainty to in vivo responses, the results of this study provide a likely neurochemical mechanism for hypercapnia-evoked bradycardia and the dysregulation of this response with exposure to prenatal nicotine, creating a higher risk for SIDS.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
1529-2401
pubmed:author
pubmed:issnType
Electronic
pubmed:day
4
pubmed:volume
26
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
21-9
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
2006
pubmed:articleTitle
Differential control of central cardiorespiratory interactions by hypercapnia and the effect of prenatal nicotine.
pubmed:affiliation
Department of Pharmacology and Physiology, The George Washington University, Washington, DC 20037, USA.
pubmed:publicationType
Journal Article, Comparative Study, In Vitro, Research Support, N.I.H., Extramural