Activation of human medial prefrontal cortex during autonomic responses to hypoglycemia
- *Division of Endocrinology, Metabolism, and Lipid Research of the Department of Internal Medicine, Washington University School of Medicine, Campus Box 8127, 660 South Euclid Avenue, St. Louis, MO 63110; and †Departments of Neurology and Radiology, Washington University School of Medicine, East Building Imaging Center, Campus Box 8225, 4525 Scott Avenue, St. Louis, MO 63110
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Edited by Marcus E. Raichle, Washington University School of Medicine, St. Louis, MO (received for review October 30, 2003)
Abstract
Studies in humans implicate the medial prefrontal cortex (MPFC) in complex cognitive and emotional states. We measured regional cerebral blood flow (CBF) four times each during euglycemia (5.2 ± 0.2 mmol/liter) and hypoglycemia (3.0 ± 0.3 mmol/liter) in nine normal human volunteers. Autonomic responses during hypoglycemia were manifested by increases in neurogenic symptoms, heart rate, and plasma levels of epinephrine, norepinephrine, and pancreatic polypeptide. Typical symptoms of hypoglycemia were mild, and none reflected evidence of cognitive or emotional stress. Quantitative CBF fell 6–8% in the cerebrum, brainstem, and cerebellum. Analysis of regional CBF differences identified neuronal activation during hypoglycemia in bilateral MPFC (areas 24 and 32) and bilateral thalamus. These results provide evidence that the MPFC participates in the autonomic responses to simple physiological stimuli in humans.
Footnotes
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↵ ‡ To whom correspondence should be addressed. E-mail: wjp{at}npg.wustl.edu.
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This paper was submitted directly (Track II) to the PNAS office.
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Abbreviations: MPFC, medial prefrontal cortex; ACC, anterior cingulate cortex; PET, positron emission tomography; CBF, cerebral blood flow; rCBF, regional CBF; MR, magnetic resonance.
- Copyright © 2004, The National Academy of Sciences
