Reversing Memory Loss Might Be Possible With Use of "Therapeutic Molecules
"It has generated a lot of interest and hope."
A scientist in Canada believes that he might be able to fix one of the defining symptoms of aging in the brain.
In a presentation last week at the American Academy for the Advancement of Science Meeting in Washington, D.C., clinical neuroscientist Etienne Sibille, Ph.D., unveiled his new treatment that might be able to restore memory loss that comes naturally with aging, or severely in brain diseases like Alzheimer’s.
Sibille, senior scientist at the Campbell Family Mental Health Research Institute, believes he has identified a problem with one key group of cells that might be responsible for the memory problems associated with aging.
He believes that the cognitive deficits — or declines in memory — can be traced to a group of somatostatin-positive cells in the brain that seem to have issues with one key receptor.
Sibille tells Inverse that he believes that he has created a new group of molecules that seem to be able to restore function to that receptor, and sets off a chain reaction that helps the brain regain the ability to encode new memories. Beyond that, they may actually protect the brain against aging-related memory loss in the first place.
“These particular receptors mediate the function of cells (somatostatin-positive cells) that are deficient in depression and during aging,” Sibille says. “Using our new molecules we can increase the function of the receptors that mediate the function of these cells. The results is a restoration of proper brain activity that is responsible for coding information, a basic process in cognition.”
"“The goal would be ‘one pill a day.’ It has generated a lot of interest and hope."
Sibille explains that these cells are a part of the brains’ GABA neurotransmitter system. GABA, short for gamma-aminobutyric acid, is an inhibitory messenger in the brain. When it binds to a cell, it represses activity in the cells that surround it, and help maintain a careful balance of signals in the brain. Sibille notes that this balance becomes impaired in patients with Alzheimer’s and depression, and previous work has shown that helping restore that balancing function can help restore memory loss in mouse models.
By helping “repair” receptors on somatostatin-positive cells, Sibille believes his molecules are a way to do just that. In a mouse trial conducted over two months, Sibille noted that in mice who had displayed memory loss associated with age, his intervention helped restore the function of GABA receptors in their somatostatin-positive cells, which improved their performance on a memory task (how well mice remembered a route through a maze) by 80 percent. He published the results of that trial in January in Molecular Neuropsychiatry.
“The aged cells regrew to appear the same as young brain cells, showing that our novel molecules can modify the brain in addition to improving symptoms,” added Sibille in a release. “We’ve shown that our molecules enter the brain, are safe, activate the target cells and reverse the cognitive deficit of memory loss.”
At the moment, Sibille has a wide range of hopes for his treatment. At the meeting, he actually floated it as a potential treatment for depression as well — adding that by restoring functionality to somatostatin-positive cells, he may be able to reverse some of the memory loss symptoms associated with the condition. He also explained that his molecules are actually a variation on benzodiazepines, which are sometimes used in tandem with anti-depressants to treat jitters or anxiety, but don’t actually treat the cognitive symptoms of depression, like memory loss.
“The overall model is consistent with what people are working on. We may have been lucky to stumble upon a type of cell that can mediate that,” he said. “If you look at diseases like depression or schizophrenia where cognitive declines are prevalent, anti-depressants don’t do anything on those symptoms.”
Clearly, Siblle has lofty aspirations for his drug, which as of now, still hasn’t been tested for safety and efficacy on humans, though he estimates that he should have those tests done in roughly two years. Though he didn’t address this in his panel, benzodiazepines can often cause dangerous withdrawal symptoms, addiction or, sometimes, death in people who take them for too long. Sibille will have to prove that his variation on them won’t have the same effects.
That’s especially important because, at the end of the day, he envisions this being sold to consumers as a type of preventative medication — something that someone who might be at risk for Alzheimer’s or maybe depression could take regularly to help stave off the effects on memory.
“The goal would be ‘one pill a day,’” he adds. “It has generated a lot of interest and hope.”
If he is able to prove his concept, Sibille may provide comfort for thousands of people each year who suffer from the effects of aging on the brain. Now it’s on him to demonstrate that it can live up to his high hopes in the future.