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Respir Physiol Neurobiol · Oct 2012
Contribution of medullary raphé to control of coughing--codeine trials in cat.
- Ivan Poliacek, Michal Simera, Marcel Veternik, Peter Machac, Helena Barani, Nadezda Visnovcova, Erika Halasova, and Jan Jakus.
- Department of Medical Biophysics, Jessenius Faculty of Medicine, Comenius University, Mala Hora 4, 03601 Martin, Slovakia. poliacek@jfmed.uniba.sk
- Respir Physiol Neurobiol. 2012 Oct 15; 184 (1): 106-12.
AbstractIn order to determine if a codeine-sensitive control system for cough exists in the medullary raphé four microinjections of codeine (3.3 and 16.5 mM; 36.6±0.7 nl 1.5 and 3 mm rostral to the obex at the depths 1.5 and 3 mm; the total dose 1.12±0.3 nmol, 9 animals) were performed on pentobarbitone anesthetized spontaneously breathing cats. Amplitudes of abdominal muscle EMG moving averages during mechanically induced tracheobronchial cough decreased by 18% compared to control coughs (p<0.05). The duration between maxima of cough diaphragm and abdominal muscle EMG discharge, cough expiratory phase duration and period of relative motor quiescence between coughs were increased (all p<0.05). Cough number, other cough parameters, and cardiorespiratory characteristics were not altered significantly. Control microinjections of artificial cerebro-spinal fluid had no effect on coughing. Codeine sensitive neurons involved in the generation or modulation of motor pattern of tracheobronchial cough are located in the medullary midline raphé nuclei; however, their contribution to codeine induced cough suppression is limited.Copyright © 2012 Elsevier B.V. All rights reserved.
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