Orexin contributes to eupnea within a critical period of postnatal development

• DOI: 10.1152/ajpregu.00156.2021
• Publication Date: 2021-08-18T12:00:49Z
• Authors: Richard L. Spinieli; Ruwaida Ben Musa; Jane Kielhofner; Jennifer Corneliu...; Kevin J. Cummings
• Keywords: Hyperoxia; Hypoxia

Orexin neurons are active in wakefulness and mostly silent sleep. In adult rats humans, orexin facilitates the hypercapnic ventilatory response but has little effect on resting ventilation. The influence of breathing early postnatal period, across states vigilance, have not been investigated. This is relevant as system may be impaired Sudden Infant Death Syndrome (SIDS) cases. We addressed three hypotheses: 1) provides a drive to breathe infancy; 2) depends stage development; 3) greater compared with Whole body plethysmography was used monitor infant at ages: days ( P) 7–8, 12–14, 17–19. Respiratory variables were analyzed (W), quiet sleep (QS), (AS), following suvorexant (5 mg/kg ip), dual receptor antagonist, or vehicle (DMSO). Effects responses graded hypercapnia ([Formula: see text] = 0.02, 0.04, 0.06), hypoxia 0.10), hyperoxia 1.0) P12–14 also tested. At P12–14, other ages, significantly reduced respiratory frequency all states, equivalent QW QS, increased [Formula: ∼5 mmHg. Suvorexant had no hypoxia. Hyperoxia eliminated effects P12–14. Our data suggest that preserves eupneic ventilation rats, specifically ∼2 wk age, perhaps by facilitating tonic peripheral chemoreflex activity.