Does mild hypoxia modulate the stimulus-evoked BOLD response?
Mayhew S, Wise R, Rogers R, Dunckley P, Tracey I, Pattinson K
University of Oxford, University of Oxford
We investigated modulations of the BOLD response by mild hypoxia for brief visual, auditory and noxious thermal stimuli. These stimuli were combined with alternating 300-second periods of mild hypoxia (16% FiO2) and normoxia (21% FiO2) in 9 healthy human subjects at 3T. We observed a significant decrease in BOLD response in visual and auditory areas during hypoxia (p<0.05). No significant hypoxia-induced modulation of BOLD response was detected in a wide network of regions of the brain that respond to painful stimulation. Our observations suggest a regional dependence of the modulatory effect of mild hypoxia on the BOLD response.