Drug that reverses genetic changes behind Alzheimer’s

New York, May 4 (IANS) A drug which is already being used to treat a neurological disorder is capable of reversing key genetic changes associated with Alzheimer's disease, says a study.

Ageing takes its toll on the brain, and the cells of the hippocampus -- a brain region with circuitry crucial to learning and memory -- are particularly vulnerable to changes that can lead to Alzheimer's disease or cognitive decline.

With the hope of counteracting the changes that can lead to these two conditions, the researchers examined the effects of a drug called riluzole which is known to affect this circuitry.

"In ageing and Alzheimer's, the chemical signal glutamate can accumulate between neurons, damaging the circuitry," said lead researcher Ana Pereira from Rockefeller University in New York, US.

"When we treated rats with riluzole, we saw a suite of changes. Perhaps most significantly, expression of molecules responsible for clearing excess glutamate returned to more youthful levels," Pereira noted.

The drug riluzole is already being used to treat amyotrophic lateral sclerosis -- a neurological disease that affects nerve cells in the brain and the spinal cord - and is therefore considered safe.

The drug, it turns out, modifies the activity of certain genes in an aged animal to resemble that of a younger rat.

For example, the researchers found that the expression of a gene called EAAT2, which has been linked to Alzheimer's and is known to play a role in removing excess glutamate from nerve fibres, declines as the animals age.

However, in rats treated with riluzole this gene's activity was brought back to its youthful levels.

The research was described in the journal Molecular Psychiatry.

Previous work by Pereira had shown that the drug prompted structural changes in rats' neurons that prevent the memory loss often seen in old animals.

Pereira is currently testing riluzole for the first time in Alzheimer's patients in a clinical trial at the Rockefeller University Hospital, an official statement said.

"We hope to use a medication to break the cycle of toxicity by which glutamate can damage the neurons that use it as a neurotransmitter, and our studies so far suggest that riluzole may be able to accomplish this," Pereira said.