In a new study, scientists have tested an experimental drug in mice that may hold promise for future Alzheimer’s treatments. The drug involves a small molecule that boosts the function of neurotransmitter (NMDA) receptors found between brain cells.
By supporting communication between brain cells, or neurons, NMDA receptors play a role in cognition and memory. Researchers have known for some time that impairment in NMDA receptors is associated with cognitive decline and amyloid buildup in Alzheimer’s patients. It’s also linked to other chronic neuropsychiatric and neurodegenerative diseases, as well as epilepsy.
Increasing activity and function in synaptic NMDA receptors through the use of this experimental drug showed it could improve memory as well as the brain’s rhythm patterns, the study concluded.
The researchers tested the drug, simply called GNE-0723 in this early stage, on mice with Alzheimer’s disease and Dravet syndrome — a rare form of epilepsy. GNE-0723 works by reducing low-frequency oscillations in the brain, a type of activity that becomes more frequent in Alzheimer’s disease and Dravet syndrome.
Reducing these oscillations led to improved cognition and memory, and even stopped epileptic activity in the mice. After being on the treatment for several weeks, the mice actually showed improvements on learning and memory tests compared to mice that were untreated.
“What we saw after the treatment were brain-wide changes in neural activity that shift the brain to a more active state that facilitates learning and memory,” Jorge Palop, Gladstone Associate Investigator and senior author of the study, said in a news release.
Though it was done in mice, the authors of the study hope it may hold potential to be further developed down the road and tested in humans.
“This is the first time we’ve explored what this type of experimental drug does in animal models,” Jesse Hanson, a scientist at Genentech and author of the study, said in the news release. “It was very gratifying to see an effect on both the brain’s electrical activity and the animals’ behavior.”
Currently, research into finding a drug to treat Alzheimer’s is divided into several different camps. Some drugs target beta-amyloid buildup, which is still considered one of the main drivers of the disease. Biogen’s aducanumab, which fights amyloid, showed promising results in recent data and is being submitted to the FDA for approval.
Other research is aiming to develop drugs that battle tau protein, inflammation or genetics that contribute to the disease. The latest study, meanwhile, may open up a pathway for a potential therapy that hones in on a specific part of the brain — NMDA receptors.
“Before now, we haven’t had ideal tools to enhance synaptic NMDA receptors,” Palop said. “Now, the ability to specifically target these receptors opens up a lot of new possibilities for treating cognitive disorders.”