title: The pre-Bötzinger complex and phase-spanning neurons in the adult rat.
abstract: To characterise respiratory neurons in the pre-Bötzinger complex of adult rats, extracellular recordings were made from 302 respiratory neurons in the ventral respiratory group of sodium pentobarbitone anaesthetised adult rats. Neurons were located 0 to 1.6 mm caudal to the facial nucleus, and ventral to the nucleus ambiguus. The pre-Bötzinger complex comprised expiratory neurons (22%, 22/100), inspiratory neurons (37%, 37/100) and phase-spanning neurons (41%, 41/100). In contrast, 80% (125/157) of Bötzinger neurons were expiratory, and 80% (36/45) of rostral ventral respiratory group neurons were inspiratory. Rostrocaudally, the pre-Bötzinger complex extended about 400 microns, starting at the caudal pole of the nucleus ambiguus compact formation. The pre-Bötzinger complex was also characterised by a predominance of propriobulbar neurons (81%, 13/16). Furthermore, 68% (33/48) of expiratory-inspiratory neurons found were located within the pre-Bötzinger complex. The variety of neuronal subtypes in the pre-Bötzinger complex, including many firing during the expiratory-inspiratory transition is consistent with the hypothesis that this nucleus plays a key role in respiratory rhythm generation in the adult rat.
authors.affiliation: Department of Physiology, University of Sydney, Australia.
authors.forename: Q J
authors.initials: QJ
authors.lastname: Sun
authors.forename: A K
authors.initials: AK
authors.lastname: Goodchild
authors.forename: J P
authors.initials: JP
authors.lastname: Chalmers
authors.forename: P M
authors.initials: PM
authors.lastname: Pilowsky
mesh_terms: D000200:Action Potentials / Q000187:drug effects / Q000502:physiology; D000367:Age Factors; D000818:Animals; D001369:Axons / Q000502:physiology; D004558:Electric Stimulation; D004594:Electrophysiology; D006710:Homocysteine / Q000031:analogs & derivatives / Q000494:pharmacology; D008526:Medulla Oblongata / Q000166:cytology* / Q000502:physiology*; D009046:Motor Neurons / Q000187:drug effects / Q000502:physiology* / Q000648:ultrastructure; D010507:Periodicity; D010791:Phrenic Nerve / Q000166:cytology / Q000502:physiology; D051381:Rats; D017207:Rats, Sprague-Dawley; D012119:Respiration; D013116:Spinal Cord / Q000166:cytology / Q000502:physiology; D014628:Vagotomy
chemical_list: D006710:Homocysteine; C007956:homocysteic acid