title: Role of the dorsal medulla in the neurogenesis of airway protection.
abstract: The dorsal medulla encompassing the nucleus of the tractus solitarius (NTS) and surrounding reticular formation (RF) has an important role in processing sensory information from the upper and lower airways for the generation and control of airway protective behaviors. These behaviors, such as cough and swallow, historically have been studied in isolation. However, recent information indicates that these and other airway protective behaviors are coordinated to minimize risk of aspiration. The dorsal medullary neural circuits that include the NTS are responsible for rhythmogenesis for repetitive swallowing, but previous models have assigned a role for this portion of the network for coughing that is restricted to monosynaptic sensory processing. We propose a more complex NTS/RF circuit that controls expression of swallowing and coughing and the coordination of these behaviors. The proposed circuit is supported by recordings of activity patterns of selected neural elements in vivo and simulations of a computational model of the brainstem circuit for breathing, coughing, and swallowing. This circuit includes separate rhythmic sub-circuits for all three behaviors. The revised NTS/RF circuit can account for the mode of action of antitussive drugs on the cough motor pattern, as well as the unique coordination of cough and swallow by a meta-behavioral control system for airway protection.
authors.affiliation: Department of Physiological Sciences, College of Veterinary Medicine, University of Florida, Gainesville, FL 32610-0144, USA. Electronic address: bolser@ufl.edu.
authors.forename: Donald C
authors.initials: DC
authors.lastname: Bolser
authors.affiliation: Department of Neurological Surgery, Kentucky Spinal Cord Injury Research Center, University of Louisville, Louisville, KY 40202, USA.
authors.forename: Teresa E
authors.initials: TE
authors.lastname: Pitts
authors.affiliation: Department of Physiological Sciences, College of Veterinary Medicine, University of Florida, Gainesville, FL 32610-0144, USA.
authors.forename: Paul W
authors.initials: PW
authors.lastname: Davenport
authors.affiliation: Department of Molecular Pharmacology and Physiology, Morsani College of Medicine, University of South Florida, 12901 Bruce B. Downs Blvd., Tampa, FL 33612-4799, USA.
authors.forename: Kendall F
authors.initials: KF
authors.lastname: Morris
mesh_terms: D000818:Animals; D003371:Cough / Q000503:physiopathology*; D003679:Deglutition; D006801:Humans; D008526:Medulla Oblongata / Q000254:growth & development* / Q000502:physiology* / Q000503:physiopathology; D009434:Neural Pathways / Q000503:physiopathology; D055495:Neurogenesis / Q000502:physiology*; D012137:Respiratory System
keywords: Airway protection; Brainstem; Breathing; Central pattern generator; Cough; Medullary neuron; Respiratory reflex; Swallow