An experimental drug that supports diseased brain cells has created hope for treatment for memory loss, poor decision-making and other mental limitations that often strike at an advanced age.
The drug can be taken as a daily pill by over-55s and clinical trials, which are expected to start within two years, show that the drug is safe and effective to prevent memory loss.
Tests in the lab showed that old animals had much better memory skills half an hour after receiving the drug. After two months of treatment, the brain cells that had shrunk in the animals had regained, scientists thought.
Etienne Sibille, of the Center for Addiction and Mental Health in Toronto, said that the treatment was not only focused on the "normal" cognitive decline leading to senior moments, but also on memory loss and mental limitations that often people with depression, schizophrenia and Alzheimer's disease.
If the drug worked out well in human trials, Sibille said it was possible that "anyone over 55-60, who might later have cognitive problems, could benefit from this treatment".
"Our findings have direct implications for poor cognition in normal aging," he said, allowing the drug to improve learning, memory, decision-making and essential life planning. "But we see this deficiency in disorders from depression to schizophrenia and Alzheimer's disease."
There are no drugs on the market that improve the type of memory loss seen in old age and psychiatric disorders such as depression and schizophrenia. But Toronto researchers believe their medicine can reverse failed memories by focusing on specific cells involved in learning and memory, and rejuvenating them. The changes that the drug causes in the brain suggest that memory loss at the beginning of Alzheimer's disease could occur and possibly slow down the onset.
Research on memory loss has shown that it is partially linked to levels of a neurotransmitter known as GABA. His normal task is to slow down the rate at which neurons fire, effectively dampening electrical "noise" in the brain. Lower this background noise and important signals in the brain can be processed more easily, according to the theory.
The new drug is a derivative of benzodiazepine, a family of drugs that includes the anti-anxiety pills Valium and Xanax. Although Valium and Xanax have broad effects in the brain, the new drug is designed to target specific GABA receptors found on neurons in important parts of the brain, such as the hippocampus, which are strongly involved in cognition.
Scientists tested the drug on mice in a maze and found that half an hour after receiving a single dose, old animals performed almost as well as young mice. The drug also restored the performance of young mice whose memories were temporarily affected by the stress to be kept in a confined space.
"An old mouse will naturally perform about 50-60% on this test, but the working memory does not work in principle, but within 30 minutes of administering the drug, their performance is down to 80-90%, so almost at the level of a young mouse, we have a quick turnaround of age-related work memory shortage and that's exciting, "Sibille told the Guardian.
In the latest study, the Toronto team showed that brain cells that had shrunk in older mice had regrowth in their drinking water after two months of administering the drug. "We can even let the brain cells grow," Sibille said.
"They tend to shrink with age and they shrink in neurodegenerative diseases.What we see is that the cells grow to a level that is fairly close to that in young animals."
Laboratory tests showed no benefit when the drug was administered to healthy young animals, suggesting that it would not work if a cognitive enhancer and healthy people gave superhuman memory skills. "It is not a drug that a student would take if they wanted to become smarter when they were studying for their exams," said Sibille. The researchers filed a patent on the drug Wednesday for a speech at the annual meeting of the American Association for the Advancement of Science in Washington DC.
Scientists are now hoping to test the drug in humans, with the first trials expected to be in people with depression. When people are in remission of depression, people with poor memory and other mental disabilities often have a relapse, said Sibille.
"If we could somehow handle those deficits, we could potentially have a major impact on the lifelong pathway of the disease in those people, and it would be a game changer in how we treat depression."