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.