Influence of pulmonary inflations on discharge of pontile respiratory neurons.
The purpose of this study was to characterize the influence of pulmonary inflations on the discharge patterns of rostral pontile respiratory neurons. Decerebrate and paralyzed cats were ventilated with a servo-respirator which produced patterns of pulmonary inflation, assessed by tracheal pressure, which paralleled alterations in integrated activity of the phrenic nerve. Neurons with respiratory-modulated neuronal activities were recorded in the pneumotaxic region of the nucleus parabrachialis medialis and Kolliker-Fuse nucleus, as well as in the trigeminal motor nucleus. Approximately equal numbers of neurons had phasic and tonic respiratory-modulated discharge patterns. The discharge patterns of most neurons were not qualitatively altered when pulmonary inflation was prevented. However, withholding inflation did cause the recruitment of some respiratory-modulated neuronal activities. Similar findings were obtained in normocapnia and hypercapnia. Results support the concept that the discharge of neurons in the pneumotaxic region may exert phasic, as well as tonic, influences on ventilatory activity.
D000818:Animals; D001794:Blood Pressure; D002245:Carbon Dioxide / Q000502:physiology; D002415:Cats; D005260:Female; D008297:Male; D009431:Neural Conduction; D010791:Phrenic Nerve / Q000502:physiology; D011149:Pons / Q000502:physiology*; D011659:Pulmonary Gas Exchange; D012119:Respiration; D012125:Respiratory Center / Q000502:physiology*; D014278:Trigeminal Nuclei / Q000502:physiology*
D002245:Carbon Dioxide