How Alzheimer's May Unfold

MONDAY, Nov. 10, 2003 (HealthDayNews) -- New information about how free radicals may contribute to the development of Alzheimer's disease has been uncovered by Ohio State University researchers.

They found that oxidation -- damage to cells caused by free radicals -- can harm certain kinds of messenger RNA (mRNA) in the brain. Messenger RNA turns DNA's genetic code into the proteins needed for healthy brain function.

In the brains of people with Alzheimer's, up to half of the mRNA are damaged by oxidation. These oxidized mRNAs may process proteins abnormally, something that may contribute to brain cell death.

"We know that free radicals can damage DNA, but nobody had looked at the effect of free radicals on RNA," study author C. Glenn Lin, an assistant professor of neuroscience, says in a prepared statement.

"When we looked for mRNA in the Alzheimer's brain, we found significant amounts of oxidized mRNA in the frontal cortex, which is one of the main areas affected by the disease," Lin says.

The findings were presented Nov. 10 at the Society for Neuroscience annual conference in New Orleans.

In another Ohio State University study presented at the same conference, scientists say they've identified a mechanism that may play a major role in the deterioration of mental ability in many elderly people.

In research with rats, the scientists found mini-strokes (which are fairly common in older brains) prevent a key brain chemical called acetylcholine from carrying messages from nerve cell to nerve cell. The integrity of nerve cells that use acetylcholine depends on a steady blood flow in the brain.

A decrease in the number of nerve cell fibers (axons) that use acetylcholine in the brain's cortex resulted in a decline in the rats' mental function, the study found.

More information

Here's where you can learn more about Alzheimer's disease.