Abstract #2761

Jezzard P, Gallichan D, Bulte D, Chiarelli P

We simultaneously acquired BOLD and CBF data from three distinct brain regionsthe visual cortex, the primary motor cortex, and the supplementary motor areawhile alternating between epochs of visual stimulation, motor stimulation, and 4 % CO2-breathing. We calculated hypercapnia calibration values (M) of 4.5, 8, and 7.5 for the visual, motor, and supplementary motor areas, respectively, and we find CBF:CMRO2 coupling ratios of ~4:1, ~3:1, and ~2.5:1 in the three regions. Understanding regional heterogeneity of neurovascular coupling is an important step towards both a better understanding of the brain, and of the imaging signals we use to investigate functional anatomy.