Mental Exercise May Help Prevent Parkinson's Disease
People who have Parkinson's disease may someday find themselves
undergoing a mental training regimen that helps them respond better
to the drugs they take and to avoid surgery.
But first, the results of animal studies by Richard E. Tessel
and his colleagues must be found to work in humans.
"Our studies hint that exercising your brain every day might be
just as important as 20 minutes of physical exercise," said Tessel,
professor of pharmacology and toxicology at the University of
Work by Tessel and Stephen R. Schroeder, director of the KU
Institute for Life Span Studies, will appear in early 1998 in the
journal Brain Research.
Most scientists interested in diseases like Alzheimer's and
Parkinson's, which stem from massive loss of brain cells, focus on
drugs and surgery, Tessel said.
But Tessel's work is related to research at other universities
suggesting that lifestyle can make a difference in the progression
of such diseases.
"Several have hinted that the more education you have, the less
likely you are to get Alzheimer's or Parkinson's," he said.
The root cause of Parkinson's is the lack of a chemical
messenger, dopamine, that serves as a relay between certain nerve
cells in the brain.
The relationship of Parkinson's to dopamine is underscored in
the name of the drug commonly used to treat Parkinson's:
In their experiments, Tessel and Schroeder used four sets of
rats. Two of the sets contained normal rats. The other two sets
contained rats that had had almost all of their dopamine-making
cells killed, in effect inducing Parkinson's in them.
One set of normal rats and one set of Parkinson's rats were put
through a training regimen that required them to push various
levers different numbers of times to get food.
A second set of normal rats and of Parkinson's rats received no
After the training, Tessel and Schroeder gave all the rats a
dopamine-like drug called apomorphine. They wanted to see if the
trained Parkinson's rats that received apomorphine would behave
better than the untrained Parkinson's rats that also got the
The researchers found that the normal rats showed little change
in behavior in response to the apomorphine, Tessel said, but the
Parkinson's rats differed sharply in their response.
"The Parkinson's rats that had NOT been trained were highly
excited and ran around in their cages after apomorphine," Tessel
said. "The Parkinson's trained rats that received apomorphine acted
exactly like the normal rats."
In experiments elsewhere, scientists have used rat-brain fetal
tissue implants containing lots of dopamine-making cells to achieve
a similar calm in rats that had had their dopamine-making cells
killed off and then received a dopamine-like drug.
Tessel said he theorized that the training regimen helped by
making more dopamine available in the brains of rats with induced
If humans follow the same patterns, he speculated, training of
some kind might reduce their need for L-dopa -- or the future
equivalent of that popular drug -- or surgical therapy or maybe a
combination of surgery and L-dopa.