Cannabinoids can trigger appetite in C. elegans, showing conserved endocannabinoid effects on hedonic feeding via olfactory neurons

Cannabinoids can produce the “munchies” effect in nematode worms, matching well known appetite effects of cannabis in humans. In the study, C. elegans worms exposed to cannabinoid signaling increased intake and specifically ate more of their favored high-calorie foods while becoming less driven toward non-favored foods. The appetite effects were tied to the worms’ cannabinoid receptors and were reproduced when the researchers replaced a C. elegans cannabinoid receptor with the human cannabinoid receptor. Mechanistically, cannabinoids altered sensitivity in key food-detecting olfactory neurons, making favored food odors more salient and non-favored odors less salient. The work suggests conserved endocannabinoid pathways across more than 500 million years of evolution, with potential implications for cannabinoid-targeted drug screening and biomedical research.