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The ventilatory response to hypoxia and hypercapnia is absent in the neonatal fat-tailed dunnart
journal contribution
posted on 2023-05-17, 16:23 authored by Simpson, SJ, Fong, AY, Cummings, KJ, Peter FrappellPeter FrappellAt birth, the newborn fat-tailed dunnart relies on cutaneous gas exchange to meet metabolic demands, with continuous lung ventilation emerging several days later. We hypothesized that the delayed expression of lung ventilation ( E V & ) in these animals is in part owing to a low responsiveness of the respiratory control system to blood gas perturbations. To address this hypothesis we assessed the ventilatory and metabolic response to hypoxia (10% O2) and hypercapnia (5% CO2) using closed-system respirometry from birth to 23 days postpartum (P). Neonatal fat-tailed dunnarts displayed no significant hypoxic or hypercapnic ventilatory responses at any age. Regardless, significant hyperventilation through a suppression of metabolic rate ( 2 O V & ) was observed at birth in response to hypercapnia and in response to hypoxia at all ages, except P12. Therefore, reliance on cutaneous gas exchange during early life may be partially attributed to reduced chemosensitivity or a lack of central integration of chemosensitive afferent information. This may be in part due to the relative immaturity of this species at birth, compared to other mammals.
History
Publication title
Journal of Experimental BiologyVolume
215Issue
24Pagination
4242-4247ISSN
0022-0949Department/School
School of Natural SciencesPublisher
Company of Biologists LtdPlace of publication
140 Cowley Rd, Cambridge, CB4 0DL United KingdomRights statement
Copyright 2012 The Company of BiologistsRepository Status
- Restricted