Effects of hypercapnia on non-nutritive swallowing in newborn lambs.
The purpose of this study was to determine the effect of hypercapnia on non-nutritive swallowing (NNS) frequency and on NNS-breathing coordination in newborn lambs. Six lambs were chronically instrumented for recording electroencephalogram, eye movements, diaphragm and thyroarytenoid muscle activity, nasal airflow and electrocardiogram. Each lamb was placed in a Plexiglas chamber and exposed to a hypercapnic gas mixture (21% O2, 5% CO2). Polysomnographic recordings were conducted in non-sedated lambs using a custom-designed radiotelemetry system. Results show that hypercapnia increased NNS frequency in all three states of alertness (p < 0.0001 to 0.03), through a specific increase in ie-type NNS. Causal mechanisms and potential consequences of such observations on aspirations and apneas, as well as on swallowing maturation, will require further studies.
Duvareille
Charles
C
Neonatal Respiratory Research Unit, Department of Pediatrics, Université de Sherbrooke, Quebec, Canada. charles.duvareille@usherbrooke.ca
Samson
Nathalie
N
St-Hilaire
Marie
M
Micheau
Philippe
P
Bournival
Véronique
V
Praud
Jean-Paul
JP
D000818:Animals; D000831:Animals, Newborn; D003679:Deglutition / Q000502:physiology*; D003964:Diaphragm / Q000503:physiopathology; D004569:Electroencephalography; D005133:Eye Movements; D006935:Hypercapnia / Q000503:physiopathology*; D017286:Polysomnography; D012132:Respiratory Muscles / Q000503:physiopathology; D012143:Respiratory Physiological Phenomena; D012756:Sheep