LOCALIZATION AND PATTERNS OF DISCHARGE OF RESPIRATORY NEURONES IN BRAIN-STEM OF CAT

Abstract

The brain-stems of 23 cats were explored with extra-cellular micropipettes from C1 to the inferior colliculus. Respiratory neurones were defined as those exhibiting periodic bursts of action potentials in step with some phase of the respiratory movements. They were found in the reticular formation, most densely beneath the region lateral to the obex. A map of iso-density contors is provided, drawn upon the floor of the 4th ventricle. Inspiratory and expiratory neurones were intermingled within the same region. The probabilities of discharge of the average inspiratory and average expiratory neurones have been calculated. The sum of these 2 probabilities remains approximately constant throughout the respiratory cycle.