The number of scientific studies on marijuana have been minimal throughout the last 100 years. This was largely due to research facilities not seeking to conduct such studies for fear of losing federal funding for other studies. With over half of U.S. states having legalized medical marijuana and a steady increase in states legalizing recreational marijuana, institutes conducting research on marijuana was overdue.
More studies on marijuana are starting to surface, and a new study conducted by Jessica Barson and Sarah Leibowitz, two neuroscientists at the Rockefeller University in New York City, has been published by one of the top scientific journal, Nature. The study sought to explain marijuana’s most commonly known side-effect, the munchies.
The team discovered that when they injected cannabinoids into mice, the drug was turning off adjacent cells that normally command the POMC neurons to slow down. POMC’s are the cluster of neurons found in the brain that scientists typically associate with base instincts like sexual arousal, alertness and feeding.
As a result, the POMC neurons’ activity leapt up. At the same time, the cannabinoids activate a receptor inside the POMC neuron that causes the cell to switch from making a chemical signal telling the brain you’re full to making endorphins, a neurotransmitter that’s known to increase appetite.
These two effects combined create a kind of runaway hungry effect. “Even if you just had dinner and you smoke the pot, all of a sudden these neurons that told you to stop eating become the drivers of hunger,” Horvath says. It’s a bit like slamming down on the brakes and finding weed has turned it into another gas pedal.