CiNet Monthly Seminar

March 14, 2019
16:00 ~ 17:00
CiNet　1F　Conference Room

“Salient metabolic features of human brain function”

Fahmeed Hyder
Professor, Biomedical Engineering
Professor, Radiology & Biomedical Imaging Technical Director
MRRC preclinical scanners Program Director
QNMR Core Center Yale University

Host : Ikuhiro Kida (PI)

Abstract:

We are exploring metabolic demands of (de)activation in relation to the resting human brain. In goal-directed fMRI scans BOLD signal is greater (or activated) compared to the baseline (or resting) condition in the frontoparietal “task-positive” network (TPN), whereas BOLD signal is reduced (or deactivated) in the “task-negative” network (TNN) or default mode network (DMN) and which includes areas like posterior cingulate. During a visual task (flashing checkerboard, 8Hz, visual angle 15×18°) lactate/BOLD signal increases are observed in the visual cortex, suggesting sensory-related aerobic glycolysis rise in non-DMN (or TPN) areas. With a cognitive task (audio-emotion portrayals with eyes closed) lactate/BOLD signal decreases are detected in posterior cingulate, signifying cognition-related aerobic glycolysis reduction in DMN (or TNN) regions. Without stimuli spontaneous BOLD signal fluctuations also reveal negatively- and positively-correlated regions, which are respectively known as DMN and non-DMN areas. However both DMN and non-DMN areas have similar levels of glucose oxidation at rest (non-sedated, eyes closed). These results indicate lack of regional specialization for aerobic glycolysis during activation, deactivation, and at rest, signifying importance of brain-wide oxidative metabolism for healthy network function in the adult human brain.