抄録
1. Effects of afferent vagal stimulation were observed on medullary respiratory discharges of urethanized rabbits.
2. In a weak inspiratory response caused by low-frequency stimulation, inspiratory bursts gave way to a continuous firing, the frequency of which, however, remained unchanged compared with that of control inspiratory discharges. The discharge intervals of expiratory neurones were prolonged.
3. In a strong expiratory response caused by high-frequency stimulation, inspiratory discharges were abolished completely. Changes of expiratory discharges were identical with those of inspiratory discharge in inspiratory response mentioned above.
4. In a respiratory acceleration, both inspiratory and expiratory discharges were inhibited numbers of firing per bursts were decreased remarkably and their discharge intervals were prolonged.
5. Based on these results, the conclusion was drawn that the inspiratory and expiratory responses to low- and high-frequency vagal stimulation were brought about by inhibition of expiratory and inspiratory neurones respectively.
