Bötzinger expiratory neurones inhibit propriobulbar decrementing inspiratory neurones.
Although bulbospinal, expiratory neurones of the Bötzinger complex (BOT E-AUG) are known to have monosynaptic inhibitory connections to many bulbospinal respiratory neurones, their connections to propriobulbar respiratory neurones have not been so well characterized. We stimulated BOT E-AUG neurones with trains of pulses, and found an inhibition of medullary and phrenic respiratory activity with phase resetting. We also examined the response of propriobulbar, decrementing, inspiratory neurones (I-DEC) to the antidromic activation of BOT E-AUG neurones from the C3 segment of the spinal cord with single shocks and found evidence for a monosynaptic inhibition of the I-DEC neurones in the post-stimulus histograms of the extracellular firing. These results were obtained in 11 pentobarbital anaesthetized cats, and provide experimental support for a recent model of respiratory rhythmogenesis.
Duffin
J
J
Department of Physiology, University of Toronto, Ontario, Canada.
Douse
M A
MA
D000818:Animals; D002415:Cats; D004558:Electric Stimulation; D005071:Evoked Potentials / Q000502:physiology; D005260:Female; D008297:Male; D008526:Medulla Oblongata / Q000166:cytology / Q000502:physiology; D008839:Microelectrodes; D009046:Motor Neurons / Q000502:physiology; D009474:Neurons / Q000502:physiology*; D010791:Phrenic Nerve / Q000502:physiology; D012119:Respiration / Q000502:physiology*; D013116:Spinal Cord / Q000166:cytology / Q000502:physiology*; D013569:Synapses / Q000502:physiology