CLINICAL ADVANCES IN DIABETES MELLITUS 

Minerva Endocrinologica 2006 June;31(2):149-58

Copyright © 2006 EDIZIONI MINERVA MEDICA

language: English

Regulation of cerebral glucose metabolism

Rao J. ¹, Oz G. ², Seaquist E. R. ¹

¹ Division of Endocrinology and Diabetes, Department of Medicine University of Minnesota Medical School, Minneapolis, Minnesota, USA 2 Center for Magnetic Resonance Research, Department of Radiology University of Minnesota Medical School, Minneapolis, Minnesota, USA

The brain uses glucose as a primary fuel for energy generation. Glucose gains entry into the brain by facilitated diffusion across the blood-brain barrier. Glucose transport may adapt during changes in cerebral glucose metabolism, neural activation and changes in plasma glucose levels. Within the brain, glucose is either oxidized to produce ATP or used to synthesize glycogen. To ensure the delivery of a continuous supply of glucose to maintain normal cellular function, the brain has developed a complex regulatory system to preserve its supply. Glucosensing neurons have been demonstrated in various regions of the brain and they appear to play an important role in not only detecting changes in brain glucose levels but also in initiating responses to maintain constant brain glucose levels. In this review, we will discuss the regulation of brain glucose metabolism (CMRgluc) and how it adapts to chronic changes in glycemia, like that seen in hyperglycemic patients with diabetes mellitus or patients with type 1 diabetes, recurrent hypoglycemia, and hypoglycemia unawareness. We will also consider the role of brain glycogen in providing fuel for energy under conditions of stress.