Effects of hypoglycemia on human brain activation measured with fMRI.
Functional magnetic resonance imaging (fMRI) was used to measure the effects of acute hypoglycemia caused by passive sensory stimulation on brain activation. Visual stimulation was used to generate blood-oxygen-level-dependent (BOLD) contrast, which was monitored during hyperinsulinemic hypoglycemic and euglycemic clamp studies. Hypoglycemia (50 +/- 1 mg glucose/dl) decreased the fMRI signal relative to euglycemia in 10 healthy human subjects: the fractional signal change was reduced by 28 +/- 12% (P < .05). These changes were reversed when euglycemia was restored. These data provide a basis of comparison for studies that quantify hypoglycemia-related changes in fMRI activity during cognitive tasks based on visual stimuli and demonstrate that variations in blood glucose levels may modulate BOLD signals in the healthy brain.
Anderson
Adam W
AW
Department of Biomedical Engineering, School of Engineering, Vanderbilt University, Nashville, TN 37232-2675, USA. adam.anderson@vanderbilt.edu
Heptulla
Rubina A
RA
Driesen
Naomi
N
Flanagan
Daniel
D
Goldberg
Philip A
PA
Jones
Timothy W
TW
Rife
Fran
F
Sarofin
Hedy
H
Tamborlane
William
W
Sherwin
Robert
R
Gore
John C
JC
D000328:Adult; D001786:Blood Glucose / Q000378:metabolism; D001931:Brain Mapping / Q000379:methods*; D002851:Chromatography, High Pressure Liquid; D004837:Epinephrine / Q000097:blood; D005934:Glucagon / Q000097:blood; D006801:Humans; D006854:Hydrocortisone / Q000097:blood; D007003:Hypoglycemia / Q000503:physiopathology*; D007328:Insulin / Q000097:blood; D008279:Magnetic Resonance Imaging; D009638:Norepinephrine / Q000097:blood; D010775:Photic Stimulation; D011863:Radioimmunoassay; D014793:Visual Cortex / Q000503:physiopathology*
D001786:Blood Glucose; D007328:Insulin; D005934:Glucagon; D006854:Hydrocortisone; D009638:Norepinephrine; D004837:Epinephrine