CHICAGO (Ivanhoe Newswire) -- Researchers from Northwestern
University report symptoms of Parkinson's disease, a
neurodegenerative disease afflicting over 1 million people in the
United States, may be improved by blocking a specific potassium
channel in a select group of brain cells.


The common symptoms of Parkinson's disease, including resting tremor,
muscle rigidity and slowed movement, are the result of dopamine loss
from the cell. Researchers have found a mechanism that may lessen the
symptoms and slow progression of the disease.


Scientists say a potassium channel unique to the affected brain
regions controls the cellular mechanism responsible for Parkinson's
disease symptoms. The potassium channel, called Kv3.4, is found in a
subset of neurons outside the basal ganglia. The basal ganglia are
structures located deep in the brain that are responsible for normal
movement such as walking. Neurons in another region of the brain
contain high numbers of potassium channels that may account for the
symptoms in Parkinson's disease patients.


Current therapies to surgically destroy these neurons or employ
electrode stimulation to disrupt neuronal activity provide
symptomatic relief. They also cause unwanted side effects such as
uncontrolled movement. "The perfect therapy for Parkinson's disease
would be to prevent neurons from exhibiting the behavior that causes
the symptoms … without altering their 'good' behaviors," says
researcher James Surmeier.


Blocking potassium channels with the Kv3.4 subunit or eliminating the
subunit using gene therapy techniques are two possible therapeutic
options, the authors write. Surmeier says, "Doing so would eliminate
the 'bad' behavior but, importantly, preserve the 'good' behavior …
of these neurons."

Reported March 25, 2003