Article by Hannah Osborne, Newsweek
Marijuana appears to improve the memory and learning abilities of old mice. Scientists discovered low doses of its main psychoactive ingredient—cannabinoid THC—can reverse the age-related decline in cognitive abilities, a finding that could lead to scientists figuring out a way of slowing brain aging in humans.
Researchers are increasingly examining THC (tetrahydrocannabinol) for its potential medical benefits. In the U.K., Oxford University recently launched a £10 million ($13 million) program to “identify new medical therapies through research into the molecular, cellular and systems mechanisms of cannabinoids.” Meanwhile, the U.S. Food and Drug Administration has now approved several medications derived from THC.
Many scientists are currently looking at its potential use as a treatment for neurological conditions, including multiple sclerosis, epilepsy and Parkinson’s disease.
In a study published in Nature Medicine on Monday, researchers led by Andreas Zimmer, from the University of Bonn, Germany, have shown how THC can provide significant benefits to mice when it comes to age-related cognitive decline.
THC interacts with receptors in the brain’s endocannabinoid system, which is involved in many physiological functions, including pain, mood, memory and appetite. Previous research has also shown activity in the endocannabinoid system declines as we get older, indicating it plays a role in the progression of aging.
To study what effect THC has on the aging brain, scientists gave low doses of THC to mice at three different life stages—two months, 12 months and 18 months. The latter two groups represented mature and old age.
The team carried out three experiments. The first involved a water maze, where mice have to learn and then remember how to navigate their way to the end. In a control group, mature and old mice performed worse than the young group. However, when treated with THC, the older groups improved at the task, while the young mice fared far worse. (The study’s authors noted that this was in “good agreement with the known detrimental effects of THC on cognition in young animals and humans.”