Nobody is claiming that smoking pot will make you smarter (and there’s plenty of anecdotal evidence that suggests that it does the opposite), but researchers at the University of Bonn are convinced that the active ingredient in pot–cannabis- can reverse the brain’s natural aging process. A University of Bonn news release reports that researchers at the school, working with others at the Hebrew University of Jerusalem, gave a small quantity of THC, the active ingredient in the hemp plant (cannabis), to mice aged two, twelve and 18 months over a period of four weeks. They then tested the learning capacity and memory performance in the animals – including orientation skills and the recognition of other mice. The researchers found that mice who were only given a placebo displayed natural age-dependent learning and memory losses, but curiously, the cognitive functions of the animals treated with cannabis were just as good as the two-month-old control animals. “The treatment completely reversed the loss of performance in the old animals,†says researcher Andreas Zimmer.
Scientists have long known that THC imitates the effect of cannabinoids produced naturally in the body, and those cannabinoids fulfill important functions in the brain. “With increasing age, the quantity of the cannabinoids naturally formed in the brain reduces,†says Zimmer. “When the activity of the cannabinoid system declines, we find rapid aging in the brain.”
To learn exactly what effect the THC treatment has in old mice, the researchers examined the brain tissue and gene activity of the treated mice. The findings were surprising: the molecular signature no longer corresponded to that of old animals, but was instead very similar to that of young animals. The number of links between the nerve cells in the brain also increased again, an important prerequisite for learning ability. “It looked as though the THC treatment turned back the molecular clock,†says Zimmer.