Marijuana and the Endocannabinoid System

During the week of October 7 in my neurochemistry class, we explored and discussed the most commonly used illegal drug in Western societies, marijuana. Throughout the week, we discussed many different aspects of the drug, such as the endocannabinoid system, its process of binding within the body, the release and uptake, and any beneficial aspects that marijuana may have for a person. Personally, I found this article to be very interesting and informative because marijuana and endocannabinoids are two things that I know very little about, and I’m sure this is true for the majority of the general public. Even after reading the paper and discussing it for a week, there is a lot that I don’t completely understand, but I hope to convey the information as accurately as possible.

In order to understand the endocannabinoid system and how marijuana is interrelated, it is important to first understand the basics of marijuana. The genus species name of the marijuana plant is Cannabis sativa. For hundreds of years, it has been used for medical and recreational purposes, and is the most widely used drugs in various countries throughout the world. Cannabis sativa contains at least 400 chemical components, in which 60 of them belong to the cannabinoid class. Tetrahydrocannabinol (THC) is the main psychoactive component of cannabis, and is responsible for giving people the feeling of being “high.” Marijuana, as well as other cannabinoids may be therapeutically useful, but this is greatly hampered by their psychotropic effects and by their potential for abuse. Research is currently being carried out to find new approaches to harness the therapeutic properties of marijuana without causing unwanted effects.

Important to the function of endocannibinoids is their binding to G-protein coupled receptors (GPCRs) on the cell surface. GPCRs work by binding a G-protein, which activates the complex by producing GTP from GDP. This complex then goes on to activate the enzyme, adenylyl cyclase, which produces the second messenger, cyclic AMP. Lastly, cyclic AMP carries out many different functions in the cell. Endocannibinoids bind to two different types of GPCRs: the CB1 receptor and CB2 receptor. The CB1 receptor is present throughout the central nervous system and is highly expressed in the cortex, hippocampus, basal ganglia, and cerebellum. They have effects on memory, movement, and nociception. Unlike CB1, the CB2 receptor in primarily expressed in the immune cells and carries out important functions in the immune system.

After their biosynthesis, endocannabinoids are released to extracellular space and activate the receptors by membrane diffusion or by a transporter. Due to their lipophilic nature, endocannabinoids can diffuse through the plasma membrane and bind to the appropriate GPCR. In addition to the psychotropic effects that marijuana has after it binds to a receptor, marijuana can also have helpful therapeutic effects for a person. Marijuana can help treat an eye disorder called, glaucoma. During our discussions during the week, we talked a lot about other therapeutic effects that marijuana can have.  One student in our class mentioned that his relative is prescribed medical marijuana to help ease chronic pain back pain. He said the marijuana has a significant impact on the reduction of his pain. We also watched a video in which a patient uses medical marijuana to reduce the symptoms of Parkinson’s disease. In the video, you could definitely observe the fact that the marijuana helped reduce the symptoms. As you can see, marijuana doesn’t only have negative effects, but it can also have helpful therapeutic effects.