Meeting Abstract
To prevent liquid entering the airway while feeding, infants must be able to coordinate breathing and swallowing. The removal of sensory signals (RLN in particular) changes kinematics, muscle function and performance of swallowing. The specific impact of a recurrent laryngeal nerve lesion on the interaction between timing of respiration and the success of swallowing, and how this interaction changes with development, is unknown. We recorded fourteen infant pigs at two ages, 7 days (early infancy) and 17 days (near weaning age). Eleven control pigs and three pigs with a recurrent laryngeal nerve lesion were recorded while feeding with highspeed videofluoroscopy. We measured the timing of a swallow relative to inspiration at the thoracic region, and the success of the swallow. Younger pigs with lesion had safer swallows than control animals, with less variability in the time of the swallow. By day 17, pigs with lesions swallowed more successfully. The controls had more unsafe swallows on day 17 than day 7. The delay in timing of respiration increased as the control and lesion pigs age. The control and lesion pigs increased the delay in timing of respiration with unsafe swallows on day 7. By day 17, the control pigs increased the delay in time when performing unsafe swallows, while the lesion animals increased the delay in time when performing safe swallows. Lesion pigs become more successful at producing safer swallows at an extended amount of time with age, suggesting that lesion animals are by some mechanism adapting to perform safer swallows. The timing of respiration does not appear to cause aspiration in the controls.
