Swallowing requires the coordination of a large number of muscles; this complexity arises partly from the need for airway protection. In the previous funding period, we added to the understanding of muscle activity and oropharyngeal kinematics in infant deglutition. However, the role of the majority of muscles during emptying of the valleculae and in the transport of the bolus past the laryngeal opening or the natural stimuli that initiate the emptying of the valleculae over maturation is not well understood. Our preliminary data suggest that two distinct pathways of bolus movement exist, either around the epiglottis/laryngeal opening (in the newborn) or over it (by the age of weaning). However the timing of the transition, from one path to the other and the associated changes in the kinematics or motor patterns, are unknown. The decerebrate pig is an excellent model for studying vallecular emptying because this phase of the swallow can be isolated experimentally. We propose to apply our existing techniques both to this model and to intact animals, in order to answer the following questions. What natural stimuli initiate vallecular emptying, and do they change during maturation? What is the pattern of muscle activity during vallecular emptying in terms of the order and amplitude of muscle activation? Does change in the consistency of the bolus alter the motor pattern during vallecular emptying, and does this change over developmental time? Does epiglottal movement result from: (i) direct muscle contraction; (ii) indirect movement of the rest of the larynx, (iii) the mechanical action of food on the epiglottis, or a combination of all three? Current studies of human dysphagia and rehabilitation rely heavily on several older studies of oral function in adult man and animal; these studies did not have the means to examine the ontogeny of vallecular function in detail. The proposed study of the maturation of motor patterns will provide an important baseline for treatment strategies aimed at human infant dysphagia.

Agency
National Institute of Health (NIH)
Institute
National Institute on Deafness and Other Communication Disorders (NIDCD)
Type
Research Project (R01)
Project #
7R01DC003604-08
Application #
6920830
Study Section
Special Emphasis Panel (ZRG1-BBBP-7 (01))
Program Officer
Shekim, Lana O
Project Start
1998-07-01
Project End
2008-07-31
Budget Start
2005-08-01
Budget End
2008-07-31
Support Year
8
Fiscal Year
2005
Total Cost
$338,606
Indirect Cost
Name
Johns Hopkins University
Department
Physical Medicine & Rehab
Type
Schools of Medicine
DUNS #
001910777
City
Baltimore
State
MD
Country
United States
Zip Code
21218
German, Rebecca Z; Crompton, A W; Gould, Francois D H et al. (2017) Animal Models for Dysphagia Studies: What Have We Learnt So Far. Dysphagia 32:73-77
Holman, Shaina Devi; Gierbolini-Norat, Estela M; Lukasik, Stacey L et al. (2014) Duration of action of bupivacaine hydrochloride used for palatal sensory nerve block in infant pigs. J Vet Dent 31:92-5
Holman, Shaina D; Campbell-Malone, Regina; Ding, Peng et al. (2014) Swallowing kinematics and airway protection after palatal local anesthesia in infant pigs. Laryngoscope 124:436-45
Holman, Shaina Devi; Campbell-Malone, Regina; Ding, Peng et al. (2013) Development, reliability, and validation of an infant mammalian penetration-aspiration scale. Dysphagia 28:178-87
Holman, Shaina Devi; Waranch, Danielle R; Campbell-Malone, Regina et al. (2013) Sucking and swallowing rates after palatal anesthesia: an electromyographic study in infant pigs. J Neurophysiol 110:387-96
Thexton, A J; Crompton, A W; German, R Z (2012) EMG activity in hyoid muscles during pig suckling. J Appl Physiol (1985) 112:1512-9
Holman, Shaina Devi; Konow, Nicolai; L Lukasik, Stacey et al. (2012) Regional variation in geniohyoid muscle strain during suckling in the infant pig. J Exp Zool A Ecol Genet Physiol 317:359-70
Wentzel, Sarah E; Konow, Nicolai; German, Rebecca Z (2011) Regional differences in hyoid muscle activity and length dynamics during mammalian head shaking. J Exp Zool A Ecol Genet Physiol 315:111-20
Konow, Nicolai; Herrel, Anthony; Ross, Callum F et al. (2011) Evolution of muscle activity patterns driving motions of the jaw and hyoid during chewing in Gnathostomes. Integr Comp Biol 51:235-46
Konow, Nicolai; Thexton, Allan; Crompton, A W et al. (2010) Regional differences in length change and electromyographic heterogeneity in sternohyoid muscle during infant mammalian swallowing. J Appl Physiol (1985) 109:439-48

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