Medullary raphe neuron activity is altered during fictive cough in the decerebrate cat.
Chemical lesions in the medullary raphe nuclei region influence cough. This study examined whether firing patterns of caudal medullary midline neurons were altered during cough. Extracellular neuron activity was recorded with microelectrode arrays in decerebrated, neuromuscular-blocked, ventilated cats. Cough-like motor patterns (fictive cough) in phrenic and lumbar nerves were elicited by mechanical stimulation of the intrathoracic trachea. Discharge patterns of respiratory and nonrespiratory-modulated neurons were altered during cough cycles (58/133); 45 increased and 13 decreased activity. Fourteen cells changed firing rate during the inspiratory and/or expiratory phases of cough. Altered patterns in 43 cells were associated with the duration of, or extended beyond, the cough episodes. The different response categories suggest that multiple factors influence the discharge patterns during coughing: e.g., respiratory-modulated and tonic inputs and intrinsic connections. These results suggest involvement of midline neurons (i.e., raphe nuclei) in the cough reflex.
Baekey
David M
DM
Department of Physiology and Biophysics, University of South Florida Health Sciences Center, Tampa 33612-4799, USA.
Morris
Kendall F
KF
Nuding
Sarah C
SC
Segers
Lauren S
LS
Lindsey
Bruce G
BG
Shannon
Roger
R
D000818:Animals; D002415:Cats; D003371:Cough / Q000503:physiopathology*; D003655:Decerebrate State; D004594:Electrophysiology; D005260:Female; D008160:Lumbosacral Plexus / Q000503:physiopathology; D008297:Male; D008526:Medulla Oblongata / Q000503:physiopathology*; D009474:Neurons / Q000502:physiology*; D010791:Phrenic Nerve / Q000503:physiopathology; D010812:Physical Stimulation; D011903:Raphe Nuclei / Q000503:physiopathology*; D012119:Respiration; D012137:Respiratory System / Q000294:innervation; D013997:Time Factors; D014132:Trachea / Q000503:physiopathology