How Much Energy Does The Brain Use

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Q A on How much The brain consumes,totalaverage, 20 percent of the body’s oxygen. This energy does number is a good reflection of the amount the brain use of energy, in theitformofaglucose, the brain uses. However, hides more interesting to perform story about the variation in energy use by the brain, including how much energy different tasks? the brain uses for differentfunctions.
Asked by Tom, a graduate student from California

FURTHER READING:

Raichle ME, Gusnard DA. Appraising the brain’s energy budget. Proc Natl Acad Sci. 2002;99:10237–9. Accessible atwww.pnas.org/content/99/16/10237.full.pdf+html Raichle ME. The brain’s dark energy. Sci Am. March 2010;302:44–9. Accessible at www.braininnovations.nl/Dark-Energy.pdf Brain Imaging Technologies:learn.genetics.utah.edu/ content/addiction/drugs/brainimage.html

We know the brain’s use of glucose varies at different times of day, from 11 percent of the body’s glucose in the morning to almost 20 percentin the evening. In addition, different parts of the brain use different amounts of glucose. We can use brain-imaging technology, such as functional magnetic resonance imaging (fMRI) and positronemission tomography (PET), to get an idea of this variation in energy use. The medial and lateral parietal and prefrontal cortices use more glucose than other parts. These regions are involved in thebrain’s default (nontask-related) activity as well as cognitive control and working memory, which is used for temporarily storing and manipulating information. The cerebellum, used for motor control andlearning, and medial temporal lobes, involved in longterm memory, use less glucose. Thus, different brain functions have different metabolic requirements. But the story is not so simple: Several factorsmake it difficult to identify specific metabolic requirements. First, we know the brain is constantly active, even at rest, but we don’t have a good estimate of how much energy it uses for this...