SUMMARY: This article talks about the endocannabinoid system (ECS) in animals. The first and second section talk about the three parts of the ECS: receptors (CBR1 and CBR2), ligands (endocannabinoids), and the ligand degrading enzymes. The receptors are G-protein coupled receptors, the ligands bind directly to these receptors, and the ligand degrading enzyme breaks down the ligands after they’ve been “done the job”. So, what is the job? Endocannabinoids work in reverse compared to neurotransmitters. They (endocannabinoids) are released by the post-synaptic cell and bind to receptors that are on the presynaptic membrane. In this way, they inhibit the action potential message from being sent. But they don’t stay bound for long. Once inhibition is achieved, they’re transported back to the post-synaptic cell and degraded by enzymes.
The ECS has been found in all animals, except for insects don’t have an ECS. Even the simplest animal, the hydra, has an ECS. The third section of this paper focuses on the research of cannabinoids and ECS in dogs. While humans and dogs do differ in the distribution of ECS receptors in the brain, this article concludes that using cannabinoids to treat a variety of conditions in dogs is promising.
LESSON COMMENTS: This is a good article (especially section 2) for teachers to read with the class. The topics that are covered in this article include: action potential, neurons, receptors/ligands binding properties, immune system function, and nervous system function. The most interesting part of this article is the way endocannabinoids work: the opposite of what is taught in textbooks about action potentials and neurotransmitter activity. G-protein coupled receptors are also an interesting topic to delve into if the class is studying sensory organs. Finally, the fact that the ECS can be found in all kinds of animals may be a good way for teachers to get students to take a deeper look at how organisms are related.
Silver, R. J. (2019). The Endocannabinoid System of Animals. Animals, 9(9), 686. doi: 10.3390/ani9090686