Scientists in the US have found a drug that is currently used to treat motor neurone disease could help prevent memory decline in aging rats. The study, which investigated the effects of the drug riluzole, is published on Monday 15 December in the journal Proceedings of the National Academy of Sciences.
Riluzole is currently prescribed to treat motor neurone disease, and is thought to work by suppressing the activity of glutamate, one of the brain’s chemical messengers. Glutamate is important for allowing communication between the nerve cells that control movement, and also plays a role in learning and memory. However, too much of the chemical can cause damage to brain cells, and excessive glutamate activity has been linked to a number of diseases including Alzheimer’s. One of the current treatments for Alzheimer’s, memantine, works by blocking glutamate to help slow the symptoms of the disease.
In the new study, researchers at The Rockefeller University and Mount Sinai School of Medicine in New York studied the effects of the drug riluzole in older rats. While one group of rats was given riluzole for 17 weeks, a second group was given a placebo. The results showed rats that were given the placebo declined in their performance in memory tasks at the end of the study, while those receiving riluzole performed at the same level at the start and end of the study.
The researchers also studied the rats’ nerve cells in part of the hippocampus, a region of the brain that is important for memory. They looked in particular at the nerve cells’ dendrites – small branches that extend from the cells, which in turn contain ‘spines’ that allow information to be received from other cells. They found that in rats treated with riluzole, the number of these spines was increased, suggesting that the connections between the cells had been strengthened.
Dr Simon Ridley, Head of Research at Alzheimer’s Research UK, the UK’s leading dementia research charity, said:
“This new study in rats sheds more light on the actions of riluzole, but we don’t yet know what effect the drug has for memory in people. It’s important to note that this research looked at age-related memory decline in rats, which is different to the memory loss caused by diseases like Alzheimer’s. Early-stage clinical trials of riluzole in people with Alzheimer’s are currently ongoing, and we’d need to see the results of these before we can know whether the drug could hold benefits for these people, or whether it could be more effective than existing symptomatic treatments.
“We urgently need better treatments for people with dementia, which is why Alzheimer’s Research UK is leading a number of initiatives to boost drug development, such as our Global Clinical Trials Fund. Continued investment in research is vital if we are to bring new dementia treatments to the people who so desperately need them.”