How pot gives people the munchies

The brain cells pinpointed by Horvath’s lab are the POMC neurons, which under normal circumstances suppress the impulse to eat. But when the researchers dosed mice with an imitation marijuana chemical, it activated the POMC neurons.

At the same time, mice that should’ve been sleeping began gobbling their chow, even though “it’s not a very exciting food for them. Imagine if we’d given them some good stuff,” Horvath says. Mice dosed with the drug might gorge on three or four times their normal amount of food, depending on how the drug was given.

Other tests showed that the active POMC cells were essential to the ferocious appetite the mice developed. Horvath suspects the POMC nerve cells could also be involved in creating the high associated with marijuana, because other studies show that the POMC cells have a role in complex behaviors beyond eating.