Although normal infants can successfully suckle at birth, the difficulties low birthweight infants experience have implications for both adequate nutrition and the subsequent transition to ingestion of solid food. Most clinical studies to date have, of necessity, been behavioral. Therefore little information exists on the mechanisms by which low birthweight infants suckle or juveniles drink. Nor is it known what role reflex maturation plays in the vital transition from suckling to drinking and mastication during the development and growth of low birthweight infants in oralpharyngeal kinematics and craniomandibular motor patterns?"""""""", is to be answered, there is no alternative but to conduct a well designed series of experiments on a viable and acceptable human analog. Of all mammals whose adult feeding and drinking patterns resemble humans, (i.e., the use of negative pressure as opposed to lapping mechanisms), only infant miniature pigs ate readily available, inexpensive, and can be managed to produce low birthweight infants in sufficient quantity for experimental studies. We are proposing to investigate the development of the feeding mechanisms in term and low birthweight (pre-term) infants in miniature pigs as an animal model of human function. Techniques of cineradiography with synchronized electromyography will be used to determine the patterns of kinematics and muscle control of elements of the craniofacial apparatus relevant to infant feeding and weaning in both term controls and low birthweight infants of different gestational ages. The project will also include an investigation of the coordination of respiration associated with feeding in both term and preterm infants. The time course of oral reflex maturation, the impact of premature birth on oral reflexes, and the correlation between weaning and reflex development will be additional facets of this project. Finally, we well quantitatively compare the ontogenetic allometry and development of musculoskeletal morphology in term and low birth weight infants. The ultimate objective of this study is to develop an animal model that can be used to address problems of feeding, as well as of coordination of feeding and respiration, that arise in low birthweight human infants.
