Laryngeal patency and expiration reflex following focal cold block of the medulla in the cat.
The involvement of the intermediate area and Bötzinger complex (BOT) of the rostral ventral respiratory group (r-VRG) in laryngeal control and generation of the expiration reflex were studied in anaesthetized non-paralyzed cats Focal cooling (to 20 degrees C) of the nucleus paraambigualis (NPA) caused changes in the frequency and timing of breathing with the concomitant rise in laryngeal resistance. Cooling of the nucleus ambiguus resulted in a consistent drop in laryngeal resistance. Alterations in timing and intensity of breathing but no changes in laryngeal patency were found during cooling of the BOT. The expiration reflex was inhibited by cooling of either the NPA or BOT. The role of these medullary regions in the control of laryngeal patency and central integration of the expiration reflex is discussed.
Jakus
J
J
Department of Biophysics, Jesenius Faculty of Medicine, Comenius University, Malá Hora, Martin, Slovak Republic.
Stránsky
A
A
Poliacek
I
I
Baráni
H
H
D000403:Airway Resistance / Q000502:physiology; D000818:Animals; D002415:Cats; D003080:Cold Temperature / Q000009:adverse effects*; D004576:Electromyography; D005260:Female; D007830:Larynx / Q000502:physiology*; D008297:Male; D008526:Medulla Oblongata / Q000502:physiology*; D010812:Physical Stimulation; D012018:Reflex / Q000502:physiology*; D015656:Respiratory Mechanics / Q000502:physiology*