Why Does Weed Make Us Hungry? New Fed-Funded Study Says It Activates Specific Hunger Neurons In Hypothalamus

It is common knowledge that marijuana consumption causes food cravings or so-called munchies, but up until now it's not been precisely determined why that happens. A new study, detailed in the journal Scientific Reports and conducted by researchers at Washington State University, sheds light on a mechanism in the brain that stimulates appetite. 

The scientists who observed marijuana’s impact on the brain in mice highlighted that these findings could be important for the development of new therapeutics to treat appetite disorders related to cancer treatments, anorexia and potentially obesity. 

Study Highlights 

Researchers first exposed mice to vaporized cannabis sativa and then used calcium imaging technology to observe how their brain cells respond. This imaging is said to be similar to a brain MRI, and while it has been previously used to research the brain's reaction to food, this seems to be the first known study to examine those features after marijuana exposure. 

What scientists have learned is that marijuana activated a set of cells in the hypothalamus when rodents anticipated and consumed palatable food that was not activated in unexposed mice. 

"When the mice are given cannabis, neurons come on that typically are not active," said Jon Davis, an assistant professor of neuroscience at WSU and corresponding author on the paper. "There is something important happening in the hypothalamus after vapor cannabis."

The study, funded by the Alcohol and Drug Abuse Research Program, the National Institute on Alcohol Abuse and Alcoholism and the U.S. Department of Agriculture, also determined that the cannabinoid-1 receptor, a known cannabis target, controlled the activity of a well-known set of "feeding" cells in the hypothalamus, called Agouti Related Protein neurons. With this information, researchers used a "chemogenetic" technique, which acts like a molecular light switch, to home in on these neurons when animals were exposed to cannabis. When these neurons were turned off, marijuana no longer stimulated appetite.

"We now know one of the ways that the brain responds to recreational-type cannabis to promote appetite," said Davis.

See Also: Why Are Cannabis Users Often Lean Despite The Munchies? Science May Have The Answer

Photo: Courtesy of Freddy G on Unsplash