Marijuana’s main psychoactive compound, THC, may improve memory, according to a new study in mice.
However, more research is needed to see whether these findings would apply to people, the researchers said.
The researchers found that old mice in the study experienced “a dramatic improvement in cognitive functions” after the animals were given small daily doses of THC for about a month, said study co-author Andreas Zimmer, a professor of molecular psychiatry at the University of Bonn in Germany. [25 Odd Facts About Marijuana]
Previous research in people — in teens and young adults — as well as in young animals has suggested that THC may actually impair cognition, but it was not clear how the compound might affect the aging brain in older individuals.
In the new study, the researchers looked at 17 young mice, which were 2 months old; 24 mature mice, which were 1 year old; and 29 mice that were 18 months old, considered old for mice. The researchers implanted small pumps into the bodies of all mice in the study. In about half of the mice in each age group, the pumps contained a small amount of THC that was released into the mice’s bodies daily for about a month. In the other half of the mice, the pumps contained a control substance, without THC.
The researchers then conducted a few behavioral experiments to test the mice’s cognitive skills, including their memory and ability to learn new information. For example, in one of the tasks, the scientists placed the mice in a pool of water with a hidden platform that allowed the rodents to escape the water once they could find it. In the control group, the mature mice and the old mice took longer to learn to climb out than the young mice.
However, both mature mice and old mice that had been treated with THC learned the task faster than the control mice in corresponding age groups.