NOTES ON MECHANISM OF RHYTHMIC RESPIRATION

Abstract

A 4 mm midline incision through the brain-stem at the level of the obex brought to an end all respiratory movements without stopping the periodic activity of respiratory cells in the medulla. This periodic activity was maintained in the absence of periodic activity in vagal and proprioceptive pathways. Progressive isolation of the brain-stem brought about a progressive decline in the number of periodically active respiratory neurones which could be found. It is concluded that the experimental results provided no evidence for respiratory pacemaker cells, capable of spontaneous discharge in the absence of activity in neighboring neural systems.