Low threshold facilitation of inspiration by lung volume increments.

Vagally mediated, volume dependent excitatory effects on phrenic nerve activity have been recently described in anesthetized dogs and pigs, but could not be ascertained in rabbits and baboons (Bartoli et al. 1975, Huszczuk et al. 1977, Cross et al. 1980, Karczewski et al. 1980). Results presented here on cats confirm and further characterize a volume dependent facilitatory effect on inspiratory intercostal and phrenic activity in this species.