While medical marijuana has been promoted as a treatment for a variety of ailments, finding anyone who promotes it as a memory boost is rare. Yet a German-Israeli team of researchers has just published a paper suggesting that at least in aging mice, marijuana does just that. Both in terms of mental performance and gene activity in the brain, treatment with pot’s active ingredient seems to restore older mice to a state resembling that of youth. But getting to that point took a month of treatments at levels that might affect mental performance as well.

THC is the molecule that gives marijuana its intoxicating impact, and it acts by altering the activity of the body’s internal cannabinoid signaling system. Previous studies have shown that the cannabinoid system slows down with age, making less of its signaling molecules and expressing less of the receptors they bind to. The researchers suspected that this drop might be linked to the decline in mental ability that also comes with age.

And that’s relatively easy to test, since you can just give the mice THC to activate their cannabinoid signaling network. So the researchers hooked up mice to a drip that fed them a constant supply of THC for four weeks.