Divya S. Bolar1,2, Bruce R. Rosen1,2, Karleyton C. Evans1,3, A Gregory Sorensen1,2, Elfar Adalsteinsson1,2
1HST/MGH/MIT Martinos Center for Biomedical Imaging, Charlestown, MA, United States; 2Harvard-MIT Division of Health Sciences & Technology, Cambridge, MA, United States; 3Department of Psychiatry, Massachusetts General Hospital, Boston, MA, United States
Hypercapnia induced by CO2 inhalation causes a robust increase in cerebral blood flow. Far less understood are the effects of CO2 on neuronal activity and cellular metabolism. In this study, a recently developed method called QUantiative Imaging of the eXtraction of Oxygen and TIssue Consumption (QUIXOTIC) was used evaluate the hypercapnic CMRO2 response in cortical gray matter of awake humans. We report a statistically significant decrease of 25.3% in cortical CMRO2 (p = 0.036), from normocapnia to hypercapnia. To our knowledge, this is the first time cortical GM CMRO2 response to hypercapnia has been assessed.