Cannabis has been used for thousands of years, both recreationally and medically. People all over the world know the effects of cannabis, yet until 20 years ago, no one knew how it worked within our bodies. In the early 1990s, research scientists identified a system they named “the endocannabinoid system”. It is made up of receptors and the chemicals that bind to these receptors. This system has been identified in the some of the most primitive creatures on earth. It has been found to be the most widespread receptor system in the human body. These receptors are found throughout the nervous system, immune tissues, blood cells, liver, lungs, and kidneys. This system appears to regulate many important physiologic pathways in the human body, including gastrointestinal activity, cardiovascular activity, pain perception, maintenance of bone mass, protection of neurons, hormonal regulation, metabolism control, immune function, inflammatory reactions, and inhibition of tumors cells.
The cannabinoid receptor system has two kinds of receptors:
1. CB1 receptors – found mostly in the brain, spinal cord and other parts of the body including the heart, uterus, testis, liver, small intestine and peripheral cells
2. CB2 receptors – found mostly on cells of the immune system, including the spleen, T-cells, B-cells and macrophages
The cannabinoid receptor system has three groups of chemicals, called cannabinoids, which can bind to the receptors:
1. Endocannabinoids – these are produced by the body, five have been identified including anandamide and 2-AG
2. Synthetic cannabinoids – these are produced by scientists in a laboratory and include dronabinol (Marinol) and nabilone (Cesamet)
3. Phytocannabinoids – these are produced by the cannabis plant; there are over 70 cannabinoids in the cannabis plant
The cannabinoids interact with the receptors, much like a lock and key. The receptor is the lock and the cannabinoid molecule is the key – when the cannabinoid “key” attaches to the receptor “lock”, which is on the cell wall, a reaction is triggered resulting in an effect on the brain and body. For instance, the area of the brain that controls memories is called the amygdala. When cannabinoids bind to the receptors on the cells of the amygdala, memory is affected. For those that suffer from past traumatic events who relive horrible memories (such as those with Post Traumatic Stress Disorder), the triggering of the cannabinoid receptor appears to change the brain function and memories are minimized.
Since the discovery of the endocannabinoid system, researchers have been working on developing synthetic cannabinoids, hoping to find a compound that gives the benefits of cannabinoids without the psychoactive effects. This is still an ongoing project. Many researchers are concentrating on studying the endocannabinoids (the cannabinoids produced in the body), in order to understand why humans make these compounds and how they regulate the many different physiologic processes in the body. And many scientists are attempting to study the effects of the phytocannabinoids; however, this area of research is somewhat hindered due to the plant’s illegality as a Schedule 1 controlled substance. The lack of research on the effects of cannabis in many medical conditions reflects this difficulty. With state-sanctioned medical cannabis laws, we are seeing more studies in this arena and hopefully will gain full understanding of what patients and which conditions may benefit from the use of cannabis.