Brain energy expenses

Richard L. Hall rhall at
Fri Sep 1 08:18:03 EST 2000

Vytautas writes:

>Richard Norman, sorry, but you are absolutely wrong.  You say literaly, that
>when we try to solve difficult tasks our brain "forgets" to make the data
>procesing necesary for keeping alive the body. Yes, one of your points is
>right, but not in the meaning you try to give it. Yes, when we do complex
>tasks the distribution of energy usage changes dramaticaly, so some regions
>of the brain, previously inactive, suddenly consume more energy, that the
>regions responsible of autonomic, somatic functions of the body. May be you
>simply did not expressed yourself clear, so I missunderstanded your text, In
>such a case sorry.

I am not sure you have made your point clearly either.  Regulation of 
autonomic functions are essentially brain stem with significant input 
from the hypothalamus.  Cortical processes involved with thought 
seldom interfere with regulation of normal homeostatic processes 
possibly because the functions are segregated or because safe guards 
exist to prevent failure of the autonomic systems.  On the other 
hand, seldom is not the same as never.  For example, scuba divers 
sometimes forget to breath!  Neither your or Richard give specific 
research supporting your statements although reason suggests validity 
in both positions.

>Hope this mesage can clear the things up. And for your
>question, Alexander, yes it is possible, and have been done already. I'm not
>sure, but I read in some scientific magazine, that the energy consumtion of
>the brain during hard intelectual work is almost the same as all the body
>uses while taking physical exercise. Certainly it is the most energy
>expensive organ. I may be wrong, the best would be if you could search for
>this data somewhere in the internet and tell us how is it truly.
>Respectfully, Vytautas.

The brain is NOT the most energy expensive organ.  The heart expends 
more calories pumping blood than the brain spends controlling and 
plotting.  My brain, however, has gotten me into many very expensive 
entanglements, but that is another couple stories.   ;-)

The "other" Richard

Richard L. Hall, Ph.D.
Comparative Animal Physiologist

University of the Virgin Islands
2 John Brewers Bay
St. Thomas, U.S.V.I. 00802

340-693-1385 FAX

rhall at

"Live life on the edge...the view is always better"  rlh


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