Sucking, swallowing, and their coordination with breathing, are often compromised in
preterm infants, yet are critical to their long-term health outcomes. Current work suggests
that external oral sensory stimuli induce rhythmic sucking, and that such stimuli hold
potential as rehabilitation strategies. However, our understanding of the impact of these
interventions on aerodigestive function is limited because human preterm infants are a
fragile research population, with restrictions on experimental manipulations. We also do not
know the role that the degree of prematurity and the subsequent neurological maturation of
the preterm infant brain plays in determining the effectiveness of oral stimulation in
facilitating feeding. Thus, the translation of these promising results into effective
interventions for promoting sustained oral feeding in preterm infants is inadequate. Using an
animal model of preterm infants, we propose to test how nutritive stimulation, in the form of
rhythmic milk delivery, functions as an intervention for improving aerodigestive function. We
will test two factors that may determine the success of this intervention: the duration of
intervention and degree of prematurity. We will apply the intervention for either a short term
(early infancy) or for a longer term (entire infancy prior to weaning). Within each treatment
duration, there will be two independent age groups, defined by respiratory status at birth: (1)
capable of independent respiration or (2) requiring bubble CPAP ventilation support. We will
compare these infants to bottle fed individuals who receive only non-nutritive stimulation
and to individuals who are only bottle fed. We have proven and validated this model for
studying aerodigestive function in preterm infants, as well as the interventions proposed. The
experimental methods will include high-speed biplanar videoflurography, electromyography
and respiration, from which we will extract outcome variables assessing airway protection,
rhythmicity of respiration, sucking and swallowing, and coordination amongst these
behaviors. The significance of this work is the determination of how, and at what age, oral
stimuli change the function and the underlying physiology of preterm infant feeding-
respiration coordination. By testing the relationship between infant neuromotor maturation
and the effectiveness of stimulation-based treatment, this work will provide a basis for the
subsequent development of new therapeutic interventions for neurological and physiological
complications which affect feeding in all infants.
