Neurokinin-1 receptor activation in Bötzinger complex evokes bradypnoea

Abstract

In the present study, we examined the role of the neurokinin-1 receptor (NK1R) in the modulation of respiratory rhythm in a functionally identified bradypnoeic region of the ventral respiratory group (VRG) in the in situ arterially perfused juvenile rat preparation. In electrophysiologically and functionally identified bradypnoeic sites corresponding to the Bötzinger complex (BötC), microinjection of the selective NK1R agonist [Sar9-Met(O2) 11]-substance P (SSP) produced a significant reduction in phrenic frequency mediated exclusively by an increase in expiratory duration (TE). The reduction was characterized by a significant increase in postinspiratory (post-I) duration with no effect on e..