Pneumotaxic centre and apneustic breathing: interspecies differences between rat and cat.

Pontine influences on the breathing pattern were studied in rats using either in vivo experiments in anaesthetized adult animals or in vitro experiments in newborn preparations. In cats, after anaesthesia and bivagotomy, pontine transection has been described as evoking an apneustic pattern of breathing (long sustained inspiratory discharges interrupted by short expiratory pauses). In rats, after anaesthesia, bivagotomy and pontine transection, apneustic patterns of breathing were not observed, either in vivo or in vitro. These results suggest interspecies differences between rat and cat in the pontine influences on the medullary respiratory generator.