Speculative link between daydreaming and Alzheimer's

Study Links Daydreaming, Alzheimer's
By CHERYL WITTENAUER, Associated Press Writer Wed Aug 24, 8:20 PM ET

ST. LOUIS - Scientists who set out to explore changes in the brain as

Alzheimer's disease progresses got a surprise: a possible link between
daydreaming and the degenerative brain disease that robs memory,
language and thought.

A new Washington University study shows the part of the brain used to
daydream is the same where Alzheimer's disease develops - in some
people - later in life. It suggests the normal brain activity of
daydreaming fuels the sequence of events leading to Alzheimer's.

"The implication, albeit a speculative one, is that those activity
patterns in young adults are the foothold onto which Alzheimer's
disease forms," said lead researcher Randy Buckner, associate professor
of psychology. He said they may lead to a life-long cascade that ends
in Alzheimer's disease in some people.

"It suggests a new hypothesis and opens an avenue in exploration,"
Buckner said. "By no means is it definitive."

The study appears in this week's The Journal of Neuroscience.

Researchers at Washington University and the University of Pittsburgh
used five imaging techniques to map the brains of 764 people. The
subjects fell into three groups - people in their 20s, and older people
with either early-stage dementia, or Alzheimer's disease.

When they compared images, they found that parts of the brain involved
in musing, daydreaming or recalling pleasant memories in young people
were where evidence of Alzheimer's disease appears.

The hallmarks of Alzheimer's, which affects 4.5 million Americans, are
brain lesions called plaques and tangles, formed from different
proteins, that are associated with nerve cells not communicating with
each other and eventually dying. The result is a progressive
deterioration of memory, learning and language.

The part of the brain involved in daydreaming is always active, even if
the mind is at rest, said William Klunk, coauthor of the study and
associate professor of psychiatry at the University of Pittsburgh.
"It's like an engine on idle," he said. "It never shuts down. That
activity might fuel the sequence of events that could lead to
Alzheimer's."

He said the connection is a "problem."

"The answer is not shutting down our brains," Klunk said.

"It means it's very important to identify changes in the brain at early
stages of illness, so that as newer interventions come along, we can
start them at a time when it makes a difference."

Until very recently, the disease was diagnosed with certainty only
after an examination of brain tissue in an autopsy. But brain imaging
technology developed by Klunk can detect the identifying plaques and
tangles.

The imaging techniques exist in research settings but are not yet a
routine clinical tool.

Buckner said even though his research correlates brain activity with
Alzheimer's, "there's a lot of evidence that suggests engaged cognition
is a good thing. That's the advice I'd give my family."

Neil Buckholtz, chief of the dementias of aging branch at the National
Institute on Aging, which funded the study, said the data are
interesting even if the conclusion is speculative.

"A critical question of Alzheimer's disease is why certain parts of the
brain have diseased nerve cells and other areas of the brain seem fine.
This paper speaks to that question."

It remains to be seen whether there's a "real relationship" between the
daydreaming part of the brain and Alzheimer's, he said.

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On the Net:

The Journal of Neuroscience: http://www.jneurosci.org/

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