title: The midbrain periaqueductal gray control of respiration.
abstract: The midbrain periaqueductal gray (PAG) organizes basic survival behavior, which includes respiration. How the PAG controls respiration is not known. We studied the PAG control of respiration by injecting D,L-homocysteic acid in the PAG in unanesthetized precollicularly decerebrated cats. Injections in different parts of the PAG caused different respiratory effects. Stimulation in the dorsomedial PAG induced slow and deep breathing and dyspnea. Stimulation in the dorsolateral PAG resulted in active breathing and tachypnea consistent with the respiratory changes during fright and flight. Stimulation in the medial part of lateral PAG caused inspiratory apneusis. Stimulation in lateral parts of the lateral and ventrolateral PAG produced respiratory changes associated with vocalization (mews, alternating mews and hisses, or hisses). D,L-homocysteic acid injections in the caudal ventrolateral PAG induced irregular breathing. These results demonstrate that the PAG exerts a strong influence on respiration, suggesting that it serves as the behavioral modulator of breathing.
authors.affiliation: Center for Uroneurology, University Medical Center Groningen, University of Groningen, 9700 RB Groningen, The Netherlands.
authors.forename: Hari H
authors.initials: HH
authors.lastname: Subramanian
authors.forename: Ron J
authors.initials: RJ
authors.lastname: Balnave
authors.forename: Gert
authors.initials: G
authors.lastname: Holstege
mesh_terms: D000818:Animals; D001931:Brain Mapping; D002415:Cats; D003964:Diaphragm / Q000187:drug effects / Q000502:physiology; D004305:Dose-Response Relationship, Drug; D004576:Electromyography / Q000379:methods; D006710:Homocysteine / Q000031:analogs & derivatives / Q000494:pharmacology; D010487:Periaqueductal Gray / Q000187:drug effects / Q000502:physiology*; D012119:Respiration; D013268:Stimulation, Chemical
chemical_list: D006710:Homocysteine; C007956:homocysteic acid