Epilepsy Drug Treats Down Syndrome

Mental symptoms eased

Down syndrome is a disease that occurs without discrimination, and is spread equally throughout the world. About 1 in every 800 births throughout the world results in a Down syndrome affected child. It is the world’s most common genetic cause for mental retardation.

Down syndrome’s most common physical characteristic is the mongoloid face of those afflicted with the disease, although there are other physical and mental symptoms. Mental symptoms range from moderate mental retardation to very mild disability. Physical symptoms also include health problems such as heart trouble.

Down syndrome is caused by the presence of a third chromosome in its sufferers. While most people carry two copies of chromosome, those with Down syndrome have a third chromosome known as chromosome 21. The additional activity of the genes on the third copy of chromosome 21 is believed to cause the symptoms of Down syndrome.

One of the biggest challenges Down syndrome sufferers face are learning disabilities. Down syndrome patients are too strongly affected by a chemical called GABA, a neurotransmitter that stops brains cells from getting too excited. Getting brain cells excited is part of the process of keeping the brain alert, which then enhances the learning process. Since Down syndrome sufferers don’t get their brains as stimulated, their ability to learn is impaired.

A recent study has found a drug once researched for epilepsy may be a solution to the learning deficiency in some Down syndrome patients. The drug called pentylenetetrazol, or PTZ, was found to improve learning in mice with a form of Down syndrome, and looks promising for human use.

The research study consisted of giving daily doses of PTZ to mice specially bred to have the same genetic differences that cause Down syndrome. Mice were put in a maze to test to measure their learning abilities. After 17 days of treatment, the Down mice were shown to explore and learn more like normal mice. The mice also acted more normal for up to two months after the drug was stopped.

The study, which appears in the journal Nature Neuroscience, suggests that PTZ can make long-term changes in the brain. PTZ seems to act by making more of the GABA transmitter available to the brain, therefore enhancing brain stimulation and the learning process.

What is holding back continued research is that PTZ is no longer approved for use in people. Human trials of the drug were limited to epilepsy research in the past. Researchers are hoping that they will able to start tests of PTZ on people as soon as human trials are approved.