Respiratory reflex by intratracheal inhalation of ammonia gas and the brain stem reticular system.

Abstract

Summary 1) In normal, decorticate, and decerebrate (with anterior and classical midcollicular sections) rabbits, an intratracheal inhalation of ammonia produced various respiratory patterns with increased or decreased rhythms and amplitudes leading to the inspiratory or expiratory breath-holding (see Table 1). After section of the vagal nerves these respiratory changes did not appear. 2) The changes of respiratory patterns evoked by ammonia inhalation were the same as those caused by electric stimulation of the brain stem reticular system. So the vagal nerves are considered to affect the respiratory renters in medulla oblongata, activating the brain stem reticular system. 3) In electronarcotized animals, this respiratory reflex shows almost the same changes as non-treated animals, but turns in reactions more or less dull and depressive. 4) Even in the cases of apneustic breathing inspiratory burst discharges are inhibited in rhythm and amplitude following ammonia inhalation.