The chemicals that cause tissue degeneration in Alzheimer's disease may be a natural part of human brain function, recent research suggests.

"You are actively forgetting and remembering all the time," said Dr. Dale Bredesen, founding president and CEO of the Buck Institute for Age Research, during a presentation Tuesday at the University of Utah. "Alzheimer's disease is just a fundamental imbalance in those signals."

Most researchers look at Alzheimer's as a disease of toxicity, said Bredesen, who works out of Novato, Calif.

"It's like having acid on your brain," he said. "Something's eating it."

But the chemical associated with tissue destruction in Alzheimer's patients is also present in the brains of young, healthy people — a phenomenon none of the more than 500,000 scientific papers published on the topic can explain.

"We argue the amyloid beta peptide does have a normal function," Bredesen said. "We think Alzheimer's is more of a signaling disorder rather than a disease of toxicity."

Bredesen's theory links brain development to brain deterioration.

As a fetus grows, it produces more nerve cells than it will ultimately use. Some of those cells build connections with one another, some die. Both outcomes are determined by naturally occurring chemicals.

Alzheimer's disease, said Bredesen, is an out-of-control example of this same process.

"The amyloid beta peptide in your brain is doing what it's supposed to do, but there's a thousand times too much of it," he said.

Bredesen and his colleagues believe netrin-1, another naturally occurring protein, has the opposite effect as amyloid beta peptide.

Preliminary lab tests using mice infected with "Mouzheimer's" support this theory. After just 10 days of treatment, mice injected with netrin-1 showed behavioral improvement.

"The idea is if you insert amyloid beta peptide into the receptor, it'll tell your nerve cell to start packing up and moving out," he said. "When you insert netrin-1, the cell gets the signal to start setting up for a party."

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