The purpose of this proposal is to perform experiments in decerebrate cats to examine four specific aims: 1. To determine the neural input from the Kolliker-Fuse nucleus (KFN) to pharyngeal respiratory muscle motoneurons located in the hypoglossal nucleus (HGN). In addition, to neural pathways, neuromediator activity of the KLN will be explored. 2. To determine the effect of airway length on the mechanical effects of pharyngeal constrictor muscle contraction. It is hypoothesized that upper airway shortening may alter the mechanical effect of contraction of these muscles, such that they will have dilatory instead of constricting action. 3. To determine the effect of vagal afferent activity on pharyngeal muscle constrictor action. It is proposed that the pharyngeal muscles that are usually pharyngeal constrictors may become dilator muscles during hypercapnia in the absence of afferent vagal feedback. 4. To determine the changes in regional structure during contracture of various pharyngeal muscles by the use of retrograde fiberoptic imaging in a closed upper airway. This work is an expansion of work conducted to date by the PI, who has recently relocated to the University of Pennsylvania.

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Research Project (R01)
Project #
5R01HL027520-19
Application #
6638219
Study Section
Special Emphasis Panel (ZRG1-ALTX-1 (03))
Program Officer
Twery, Michael
Project Start
1981-07-01
Project End
2006-03-31
Budget Start
2003-04-01
Budget End
2006-03-31
Support Year
19
Fiscal Year
2003
Total Cost
$356,625
Indirect Cost
Name
University of Pennsylvania
Department
Internal Medicine/Medicine
Type
Schools of Medicine
DUNS #
042250712
City
Philadelphia
State
PA
Country
United States
Zip Code
19104
Brennick, Michael J; Gefter, Warren B; Margulies, Susan S (2007) Mechanical effects of genioglossus muscle stimulation on the pharyngeal airway by MRI in cats. Respir Physiol Neurobiol 156:154-64
Brennick, Michael J; Pickup, Stephen; Cater, Jacqueline R et al. (2006) Phasic respiratory pharyngeal mechanics by magnetic resonance imaging in lean and obese zucker rats. Am J Respir Crit Care Med 173:1031-7
Brennick, Michael J; Pickup, Stephen; Dougherty, Lawrence et al. (2004) Pharyngeal airway wall mechanics using tagged magnetic resonance imaging during medial hypoglossal nerve stimulation in rats. J Physiol 561:597-610
Kuna, Samuel T; Brennick, Michael J (2002) Effects of pharyngeal muscle activation on airway pressure-area relationships. Am J Respir Crit Care Med 166:972-7
Kuna, S T (2001) Effects of pharyngeal muscle activation on airway size and configuration. Am J Respir Crit Care Med 164:1236-41
Kuna, S T (2000) Respiratory-related activation and mechanical effects of the pharyngeal constrictor muscles. Respir Physiol 119:155-61
Kuna, S T; Remmers, J E (1999) Premotor input to hypoglossal motoneurons from Kolliker-Fuse neurons in decerebrate cats. Respir Physiol 117:85-95
Kuna, S T; Vanoye, C R (1999) Mechanical effects of pharyngeal constrictor activation on pharyngeal airway function. J Appl Physiol 86:411-7
Kuna, S T; Vanoye, C R (1997) Respiratory-related pharyngeal constrictor muscle activity in decerebrate cats. J Appl Physiol 83:1588-94
Sant'Ambrogio, G; Kuna, S T; Vanoye, C R et al. (1997) Activation of intrinsic laryngeal muscles during cough. Am J Respir Crit Care Med 155:637-41

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