title: Upper and lower esophageal sphincter kinetics are modified during maturation: effect of pharyngeal stimulus in premature infants.
abstract: BACKGROUND
  We hypothesized that changes in proximal and distal esophageal sphincter kinetics evoked upon pharyngeal provocation undergo longitudinal maturation.
  
  
  METHODS
  Pharyngeal stimulation-induced reflexes were characterized using novel pharyngo-esophageal motility methods in 19 healthy premature neonates, studied at 34.7 ± 0.8 wk (time-1) and 39.3 ± 1.1 wk postmenstrual age (time-2). Graded volumes of air (290 infusions) and sterile water (172 infusions) were infused to define sensory-motor characteristics of upstream (pharyngeal reflexive swallow, PRS) and downstream (pharyngo-lower esophageal sphincter relaxation reflex, PLESRR) esophageal reflexes. Data displayed as mean ± SE.
  
  
  RESULTS
  Threshold volumes were similar with air and water for PRS and PLESRR at time-1 and time-2. Multiple PRS responses were noted with water stimulus and were different between the media (time-1 vs. air, P < 0.0001; time-2 vs. air, P = 0.0003). Dose-response relationships for water were significant (P < 0.01 for PRS and PLESRR time-1 and time-2), but not with air.
  
  
  CONCLUSIONS
  Significantly, the recruitment frequency of PRS and PLESRR increases with maturation, liquid is a superior medium for evoking such swallowing reflexes, and stimulus-response relationships for these reflexes are evident. These changes in aerodigestive protective reflexive activity may indicate differences in modulation of excitatory and inhibitory pathways during longitudinal postnatal maturation.
authors.affiliation: 1] Department of Pediatrics, Sections of Neonatology, Pediatric Gastroenterology and Nutrition, The Ohio State University College of Medicine, The Research Institute at Nationwide Children's Hospital, Columbus, Ohio [2] The Neonatal and Infant Feeding Disorders Program, The Research Institute at Nationwide Children's Hospital, Columbus, Ohio.
authors.forename: Sudarshan R
authors.initials: SR
authors.lastname: Jadcherla
authors.affiliation: The Neonatal and Infant Feeding Disorders Program, The Research Institute at Nationwide Children's Hospital, Columbus, Ohio.
authors.forename: Theresa R
authors.initials: TR
authors.lastname: Shubert
authors.affiliation: 1] Department of Pediatrics, Sections of Neonatology, Pediatric Gastroenterology and Nutrition, The Ohio State University College of Medicine, The Research Institute at Nationwide Children's Hospital, Columbus, Ohio [2] The Neonatal and Infant Feeding Disorders Program, The Research Institute at Nationwide Children's Hospital, Columbus, Ohio.
authors.forename: Ish K
authors.initials: IK
authors.lastname: Gulati
authors.affiliation: 1] Department of Pediatrics, Sections of Neonatology, Pediatric Gastroenterology and Nutrition, The Ohio State University College of Medicine, The Research Institute at Nationwide Children's Hospital, Columbus, Ohio [2] The Neonatal and Infant Feeding Disorders Program, The Research Institute at Nationwide Children's Hospital, Columbus, Ohio.
authors.forename: Preceousa S
authors.initials: PS
authors.lastname: Jensen
authors.affiliation: Center for Biostatistics, The Ohio State University College of Medicine, Columbus, Ohio.
authors.forename: Lai
authors.initials: L
authors.lastname: Wei
authors.affiliation: Division of Gastroenterology and Hepatology, Medical College of Wisconsin, Milwaukee, Wisconsin.
authors.forename: Reza
authors.initials: R
authors.lastname: Shaker
mesh_terms: D003679:Deglutition; D049630:Esophageal Sphincter, Lower / Q000502:physiology*; D049631:Esophageal Sphincter, Upper / Q000502:physiology*; D004947:Esophagus / Q000502:physiology; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature / Q000502:physiology; D008137:Longitudinal Studies; D008365:Manometry; D010528:Peristalsis; D010614:Pharynx / Q000502:physiology*; D012018:Reflex; D012684:Sensory Thresholds