How cannabis triggres appetite for favorite food and insatiable hunger or hedonism across the animal kingdom

Amazing stuff! Is that actually the real reason why so many people use cannabis? 😊 The worms were bathed in a solution of an endocannabinoid!

"... When under the influence, Caenorhabditis elegans worms choose to feed for longer than normal, and show a stronger preference for their favourite high-quality foods over less nutritious options.

The study ... suggests that the mechanism by which cannabis affects appetite evolved more than 500 million years ago, when the evolutionary paths of C. elegans and humans diverged. This commonality across the animal kingdom suggests that C. elegans could be used to study how cannabis affects the human nervous system. ...

High and hungry

... Cannabinoid molecules derived from the cannabis plant bind to the same receptors as molecules naturally found in the body, called endocannabinoids. Those receptors are found in the brain and many other tissues, and the endocannabinoid system is thought to regulate key functions, such as sleep, memory, anxiety and eating. ...
To investigate the behavioural effects of cannabinoids, the researchers immersed the worms in a solution of the endocannabinoid anandamide before placing them in the maze. ...
The worms that received this endocannabinoid bath did seem to develop a bigger appetite. When in the maze, they showed a stronger preference for nutritionally superior bacteria than did their sober peers, and spent more time eating. Worms under the influence also showed less interest in nutritionally inferior bacteria. ..."

From the abstract:

"The ability of cannabis to increase food consumption has been known for centuries. In addition to producing hyperphagia, cannabinoids can amplify existing preferences for calorically dense, palatable food sources, a phenomenon called hedonic amplification of feeding. These effects result from the action of plant-derived cannabinoids that mimic endogenous ligands called endocannabinoids. The high degree of conservation of cannabinoid signaling at the molecular level across the animal kingdom suggests hedonic feeding may also be widely conserved. Here, we show that exposure of Caenorhabditis elegans to anandamide, an endocannabinoid common to nematodes and mammals, shifts both appetitive and consummatory responses toward nutritionally superior food, an effect analogous to hedonic feeding. We find that anandamide’s effect on feeding requires the C. elegans cannabinoid receptor NPR-19 but can also be mediated by the human CB1 cannabinoid receptor, indicating functional conservation between the nematode and mammalian endocannabinoid systems for the regulation of food preferences. Furthermore, anandamide has reciprocal effects on appetitive and consummatory responses to food, increasing and decreasing responses to inferior and superior foods, respectively. Anandamide’s behavioral effects require the AWC chemosensory neurons, and anandamide renders these neurons more sensitive to superior foods and less sensitive to inferior foods, mirroring the reciprocal effects seen at the behavioral level. Our findings reveal a surprising degree of functional conservation in the effects of endocannabinoids on hedonic feeding across species and establish a new system to investigate the cellular and molecular basis of endocannabinoid system function in the regulation of food choice."

Drugs give biology’s favourite worms the munchies too

The conserved endocannabinoid anandamide modulates olfactory sensitivity to induce hedonic feeding in C. elegans (open access)

Figure 6A model for AEA-induced hedonic feeding

In this genetically engineered C. elegans, neurons that respond to cannabinoids appear green. Wow, almost the whole worm is green!