Researchers have discovered what spurs a case of the "munchies" after using marijuana, pointing to brain neurons in a study published in the journal Nature.
Led by Tamas Horvath, researchers from the Yale University School of Medicine set out to observe circuitry in the brain promoting eating by actively manipulating pathways in cells responsible for mediating marijuana's actions in transgenic mice. By monitoring how the brain's appetite center acts in response to marijuana, researchers were able to determine what drives the uncontrollable urge to eat after marijuana is used and how the same mechanism in charge of turning off feeding ends up promoting eating.
"It's like pressing a car's brakes and accelerating instead," explained Horvath, director of the Cell Signaling and Neurobiology of Metabolism program in Yale and Section of Comparative Medicine chair. "It fools the brain's central feeding system."
Researchers were surprised to find that the very neurons thought to be shutting down appetite were being activated suddenly, prompting hunger even when a subject was already full.
Aside from simply explaining what causes the munchies, researchers believe their findings may be utilized in helping patients with cancer eat better by helping them regain their appetite during treatment.
It has long been established that cannabis use leads to increased appetite as well as that activating the cannabinoid receptor 1 can promote overeating. Pro-opiomelanocortin (POMC) neurons, on the other hand, have been identified as key drivers to controlling the appetite when full.
The munchies is a result of CB1R activating and affecting POMC neurons but further research is required to validate the findings of this study. Horvath and colleagues are looking into determining if CB1R activation has anything to do with getting high with marijuana.
The study received funding support from the Deutsche Forschungsgemeinschaft, the Helmholtz Society, The Klarmann Family Foundation, the American Diabetes Association and the National Institutes of Health.
Other researchers involved in the study include: Marco Koch, Sabrina Diano, Luis Varela, Xiao-Bing Gao, Jae Geun Kim, Marcelo Dietrich, Jung Dae Kim, Klara Szigeti-Buck, Francisco Hernandez, Michael Cowley, Stephanie Simonds, Ingo Bechmann, Carloss Castorena, Pasko Rakic, Claudia Vianna, Yury Morozov and Joel Elmquist.
According to the United Nations, nearly 159 million people around the globe use pot. That's over 3.8 percent of the population who have experienced dealing with post-marijuana munchies. In the United States, more than 94 million people have admitted to using pot at least once.
