title: Sub-cortical and brainstem sites associated with chemo-stimulated increases in ventilation in humans.
abstract: We investigated the neural basis for spontaneous chemo-stimulated increases in ventilation in awake, healthy humans. Blood oxygen level dependent (BOLD) functional MRI was performed in nine healthy subjects using T2 weighted echo planar imaging. Brain volumes (52 transverse slices, cortex to high spinal cord) were acquired every 3.9 s. The 30 min paradigm consisted of six, 5-min cycles, each cycle comprising 45 s of hypoxic-isocapnia, 45 s of isooxic-hypercapnia and 45 s of hypoxic-hypercapnia, with 55 s of non-stimulatory hyperoxic-isocapnia (control) separating each stimulus period. Ventilation was significantly (p<0.001) increased during hypoxic-isocapnia, isooxic-hypercapnia and hypoxic-hypercapnia (17.0, 13.8, 24.9 L/min respectively) vs. control (8.4 L/min) and was associated with significant (p<0.05, corrected for multiple comparisons) signal increases within a bilateral network that included the basal ganglia, thalamus, red nucleus, cerebellum, parietal cortex, cingulate and superior mid pons. The neuroanatomical structures identified provide evidence for the spontaneous control of breathing to be mediated by higher brain centres, as well as respiratory nuclei in the brainstem.
authors.affiliation: Department of Respiratory Medicine, National Heart and Lung Institute, Imperial College School of Medicine, Charing Cross Hospital, London, UK.
authors.forename: Leanne C
authors.initials: LC
authors.lastname: McKay
authors.forename: Hugo D
authors.initials: HD
authors.lastname: Critchley
authors.forename: Kevin
authors.initials: K
authors.lastname: Murphy
authors.forename: Richard S J
authors.initials: RS
authors.lastname: Frackowiak
authors.forename: Douglas R
authors.initials: DR
authors.lastname: Corfield
mesh_terms: D000328:Adult; D001921:Brain / Q000502:physiology*; D001931:Brain Mapping; D002245:Carbon Dioxide / Q000097:blood; D005260:Female; D006801:Humans; D006935:Hypercapnia / Q000503:physiopathology*; D000860:Hypoxia / Q000503:physiopathology*; D007090:Image Interpretation, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D013058:Mass Spectrometry; D010100:Oxygen / Q000097:blood; D012123:Pulmonary Ventilation / Q000502:physiology*; D012815:Signal Processing, Computer-Assisted; D055815:Young Adult
chemical_list: D002245:Carbon Dioxide; D010100:Oxygen