A new study shows that a mouse model can be used to investigate how these substances and environmental factors trigger symptomatic attacks. The researchers also identified two drugs that can prevent attacks of such disorders in mice.

The study is the first to use mice to investigate triggers of episodic attacks, which are much more difficult to study in humans. Though the symptoms of episodic disorders vary, the fact that many of them share the same trigger factors may suggest a common disease mechanism.

"We finally have a model we can use to find out how these triggers destabilize nervous system function," says senior author Ellen Hess, Ph.D., of the Department of Neurology at Johns Hopkins Hospital, where the study was conducted. It was funded in part by the National Institute of Neurological Disorders and Stroke (NINDS) and appears in the August, 2002, issue of Pharmacology, Biochemistry and Behavior.

Dr. Hess and her colleagues studied a strain of mice with a gene mutation that causes them to have attacks of dyskinesia, or abnormal movements several times a day. The mutation affects calcium ion channels tiny "gates" in cell membranes that control movement of electrically charged calcium ions into and out of cells. The movement disorder caused by this mutation is known as tottering syndrome in mice. The symptoms in tottering mice are similar to those of an episodic movement disorder in humans known as paroxysmal dyskinesia.

The researchers exposed the tottering mice to the most common triggers of human episodic disorders stress, caffeine, and ethanol and found that all three of these factors generated attacks in the mi
'"/>

Contact: Tania Zeigler
zeiglert@ninds.nih.gov
301-496-5751
NIH/National Institute of Neurological Disorders and Stroke
5-Aug-2002