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Marijuana, long considered the bane of short-term memory, could actually reverse the gradual decline in learning and memory that tends to come with age, researchers said this week after experimenting on mice.
They found that daily low doses of marijuana improved learning and memory performance in older mice, seemingly restoring their mental age to that of younger mice.
The psychoactive ingredient in pot could have significantly different effects on older animals’ brains than on those of younger animals, researchers said. That positive impact, if extended to older humans, could lead to treatment of cognitive decline that comes with old age, including dementia.
“It looked as though the THC treatment turned back the molecular clock,” neurobiologist Andreas Zimmer of the University of Bonn in Germany said in a press statement.
Zimmer’s team gave small doses of THC, an active ingredient in marijuana, drip by drip to young and older mice. It was too low a dose to intoxicate the mice but enough to see its impact on receptors in the brain and nervous system that control appetite, mood and memory.
In cognition tests using a water maze, younger mice outscored the older ones, as expected. But when given doses of THC, older mice greatly improved their performance so that they did as well as younger, drug-free mice in a control group.
The findings by scientists at the University of Bonn and the Hebrew University of Jerusalem were published in the journal Nature Medicine.