
                         Roanoke Times
                 Copyright (c) 1995, Landmark Communications, Inc.

DATE: THURSDAY, July 27, 1995                   TAG: 9507270061
SECTION: NATIONAL/INTERNATIONAL                    PAGE: A-14   EDITION: METRO 
SOURCE: Associated Press
DATELINE: BAR HARBOR, MAINE                                LENGTH: Medium

ENERGY LOSS KILLS BRAIN CELLS

Alzheimer's disease and other age-related brain disorders may be the result of a catastrophic energy shortage that develops in the brain as tiny chemical fires inside nerve cells flicker and go dark, a researcher said Wednesday.

Examinations of the brains of people who have died of Alzheimer's or Huntington's disease have found elevated levels of genetic mutations in the chemical powerhouses called mitochondria, said Douglas C. Wallace, a geneticist at Emory University School of Medicine in Atlanta.

``It's well established that our energy capacity declines with age,'' Wallace said at a meeting on genetics at the Jackson Laboratory in Bar Harbor. ``The brain is the organ most reliant on energy.''

The idea that the brain's cells might gradually run out of energy with aging could help explain why people who inherit a disease such as Alzheimer's don't show symptoms until late in life, Wallace said.

With many inherited diseases, the havoc caused by genetic mutations can begin at conception, but the picture is more complex with disorders such as Alzheimer's, Huntington's and Parkinson's disease, Wallace said.

Those diseases are often related to inherited genetic abnormalities, but the abnormalities seemingly have no effect for decades.

Wallace has proposed that the inherited mutations are somehow related to mitochondria. As mitochondrial mutations increase with age, the mitochondria stop working and the cells in which they reside die.

Because brain cells are heavy energy users, they may be the first to die as these mutations increase, Wallace said. The death of brain cells would in turn give rise to brain disorders.

Nancy Wexler of Columbia University, a pioneer in Huntington's disease research, said Wallace's work provided an important clue to the biology of the disorder.

``I think that Doug Wallace has been doing extremely intriguing work,'' she said.

In his latest study, Wallace looked at various regions of the brains of people who had died of Huntington's disease and compared them with the brains of people who had died of other causes.

The Huntington's victims had 11 times the level of mitochondrial mutations in their temporal lobes compared with the controls, Wallace said.

by CNB