Maturational Change in Quiet Respiration Versus Respiration While Feeding In Infant Mammals

Abstract

Respiratory rhythm and rate differ in quiet respiration as compared to respiration when infants are suckling and swallowing. How this difference changes in neonates up through the time of weaning is unknown. We tested the hypotheses that (1) rhythm and rate change with age as a function of increasing size but that (2) significant changes in the coordination of respiration with swallowing reflect an increased ability to protect the airway in advance of weaning. We obtained a sample of 9 infant pigs from two unrelated litters and measured quiet respiration, either while sleeping or anesthetized, from 3 to 24 days of age. In the same animals, we measured respiration while feeding from 7 to 24 days of age. Quiet respiration was recorded with a plesthymograph, either while animals were sleeping or lightly anesthetized. Respiration and feeding was recorded using simultaneous high speed videoflurography (XROMM) and plesthysmography. We found minor changes with age in quiet respiration. The within‐session, usually about 1 minute, variation in respiratory rate, decreased significantly with age. Variation in respiration during feeding did not change with age. However, the timing of the coordination between swallowing and respiration changed significantly as animals approached weaning age. The maturational differences in the two types of breathing may reflect different aspects of development. The reduction in variation in quiet respiration may be due to a maturing nervous system, whereas the changes in timing and coordination between swallowing and breathing may be necessary for airway protection as young mammals move to eating solid food.Support or Funding InformationThis work is supported by NIH HD088561 to RZG.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.