Synaptic dysfunction in Huntington's disease

Huntington's disease is a hereditary disorder that primarily affects the brain, leading to death within just over a decade.

There is no treatment for the disease at present, but researchers at Lund University in Sweden believe that a medicine used for Alzheimer’s disease could alleviate some of the symptoms.

Huntington’s disease is caused by a mutation of a gene that the produces the Huntington protein. This protein influences a number of processes in the cells of the brain. The disorder first appears as symptoms like personality changes and depression, followed by dementia, weight loss, and jerky movements (which is why it used to be called Huntington's chorea, chorea - from the greek word for dance).

A research team at Lund, headed by Professor Patrik Brundin, has long been studying Huntington’s disease in order to elucidate its complex mechanisms. Ruben Smith, a doctoral student in the group, supervised by Associate Professor Jia-Yi Li, will soon be defending a dissertation in which he studied a certain type of nerve cells called cholinergic neurons. These nerve cells release acetylcholine, one of the body’s most common and important signal substances.

“It was previously believed that these nerve cells were not affected by Huntington’s, but we show that their function is probably seriously impaired by the disorder," he says.

The discovery opens the possibility of counteracting the disease by reinforcing the production of acetylcholine in the cholinergic nerve cells. Substances that have this effect already exist: they are used to treat Alzheimer’s disease, in which cholinergic neurons are also damaged.

“A couple of studies have been done with this type of medication for Huntington’s patients, but they have involved a small number of patients and a short time period. We think our results justify studies on a larger scale. After all, the drug is already approved for use," says Ruben Smith.

If the medication has an effect, it will probably impact memory and thinking primarily, not motor symptoms. The medicine would not halt the course of the disease: it would merely alleviate it. But considering the fact that there is no treatment whatsoever today, this would be a step forward.

The dissertation is titled Communication Breakdown - Synaptic Dysfunction in Huntington’s Disease. It will be defended on June 16. A summary is available at http://theses.lub.lu.se/postgrad/. Enter Huntington’s in the search box