Document Detail

Functional recovery of the ventilatory chemoreflexes after partial chronic denervation of the nucleus tractus solitarius.
MedLine Citation:
PMID:  2400910     Owner:  NLM     Status:  MEDLINE    
In pentobarbitone-anesthetized cats breathing spontaneously, we studied whether excision of one petrosal ganglion would modify the reflex efficacy of the remaining carotid and aortic chemoafferences in ventilatory control. Resting ventilation was not affected shortly after the ganglionectomy, but decreased sensitivities and reactivities for changes in tidal volume and respiratory frequency were revealed by dose-response curves for ventilatory chemoreflexes evoked by NaCN i.v. After 2 weeks of ganglionectomy, basal tidal volume was increased, being slightly reduced by contralateral carotid neurotomy, but persisting above control after section of all buffer nerves. The ventilatory chemosensory drive--tested by breathing 100% O2--was unmodified with respect to the acute condition, but the tonic ventilatory influence exerted by the right carotid nerve was diminished. Dose-response curves for reflex changes in tidal volume exhibited increased sensitivity, while those for changes in respiratory frequency showed increased reactivity. Thus, partial chemosensory denervation of the nucleus tractus solitarius triggers a slowly developing increase in the reflex efficacy of the remaining chemosensory inputs. The recovery of sensitivity for reflex changes in tidal volume required the presence of contralateral carotid afferents, while the increased reactivity in respiratory frequency needed the integrity of aortic afferents. The results also suggest an enhanced contribution of central structures other than chemosensory inputs in respiratory control after partial deafferentation.
J Eugenin; C Larrain; P Zapata
Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  Brain research     Volume:  523     ISSN:  0006-8993     ISO Abbreviation:  Brain Res.     Publication Date:  1990 Jul 
Date Detail:
Created Date:  1990-10-23     Completed Date:  1990-10-23     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  0045503     Medline TA:  Brain Res     Country:  NETHERLANDS    
Other Details:
Languages:  eng     Pagination:  263-72     Citation Subset:  IM    
Laboratory of Neurobiology, Catholic University of Chile, Santiago.
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MeSH Terms
Aorta / innervation
Carotid Arteries / innervation
Glossopharyngeal Nerve / physiology
Medulla Oblongata / physiology*
Reflex / drug effects
Respiration* / drug effects
Sodium Cyanide / pharmacology
Tidal Volume
Reg. No./Substance:
143-33-9/Sodium Cyanide

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