High-free weed sounds like something scientists shouldn’t meddle with, like a spider-goat hybrid or fat-free frozen yogurt or some other affront to creation. But bear with me here. There’s actually some good thinking behind this one.

Speaking to Wired, University of East Anglia researcher Peter McCormick explained how the skunk strain led his team to what’s being touted as a breakthrough in medical marijuana.

“A current strain of marijuana known as skunk has high levels of THC [tetrahydrocannabinol], which resulted in an increase of adolescents having psychedelic episodes,” McCormick explained. “Maybe large amounts of THC were somehow working through the serotonin receptor and giving kids this overdose in terms of memory and the high feeling — typically it’s in lower doses.”

McCormick’s team, working with the University of Pompeu Fabra in Barcelona, determined that there was one pathway in the brain activating THC’s pain relieving effects and an entirely separate one responsible for side effects like memory impairment, paranoia, and making you giggle till you cry.

The team’s findings were recently published in PLOS Biology journal, which showed you could essentially create a wall between the cannabinoid receptor’s in mice brains, allowing only the pain relief effects to activate. If they can successfully recreate those results in humans, it could open the door to safer THC treatments.

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