Cannabinoids used in worms can help regulate various body systems

New research conducted by the University of Oregon, US, has revealed that worms exposed to cannabinoids, the active compounds found in marijuana, exhibit an increased preference for certain types of food.

The study, published in Current Biology, led by neuroscientist Shawn Lockery in the College of Arts and Sciences, sheds light on the potential role of cannabinoids in regulating appetite and food preferences in the body, and could aid in the development of more targeted drugs that leverage the endocannabinoid system.

The endocannabinoid system is a complex signalling network that helps regulate various body systems, including appetite, mood, and pain sensation. It consists of cannabinoid receptors, which are proteins found throughout the body and brain, and endocannabinoids, which are naturally occurring molecules that interact with these receptors to send chemical messages. However, cannabinoids in marijuana, such as THC, also interact with cannabinoid receptors, leading to psychoactive effects and other physiological changes.

Inspired by the recent legalisation of marijuana for recreational use in Oregon, Lockery and his team turned to a species of tiny worms called C. elegans, which are commonly used in research due to their simple nervous system and well-understood genetics. The team soaked the worms in anandamide, an endocannabinoid that activates cannabinoid receptors, and then subjected them to a food choice experiment using a T-shaped maze. One side of the maze contained high-quality food, while the other side had lower-quality food.

Under normal conditions, the worms showed a preference for the higher-quality food. However, when exposed to anandamide, their preference for the higher-quality food became even stronger, with the worms actively seeking out and staying longer at the high-quality food source. 

Further experiments conducted by Lockery’s team revealed that anandamide affected specific neurons in the worms, making them more sensitive to the smell of higher-quality food and less sensitive to the smell of lower-quality food. This suggests that the endocannabinoid system plays a role in modulating sensory perception related to food preferences.

One potential application of this research is in the development of drugs that target the endocannabinoid system for medicinal purposes. Currently, cannabinoids have broad-ranging effects in the body due to the widespread distribution of cannabinoid receptors, which can result in unwanted side effects. However, by better understanding the specific pathways and proteins involved in the endocannabinoid system, more targeted drugs with fewer side effects could be developed. Worms, with their well-characterised genetics, offer a valuable tool for studying these pathways and identifying potential drug targets.

Lockery concluded that the study provides important insights into the roles of cannabinoids in the body and how they influence food preferences. The findings highlight the potential of worms as a model organism for studying the endocannabinoid system and could pave the way for the development of more effective and targeted drugs that leverage this system for therapeutic purposes.