The Science of Cannabis


The Endocannabinoid System

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”.  This system is located in our brains and bodies.  The system is made up of cell receptors and of 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, explaining why cannabis has so many different effects. The endocannabinoid 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: 
•     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 
•     CB2 receptors – found mostly on cells of the immune system, including the spleen, T-cells, B-cells and macrophages

A group of compounds, called cannabinoids, bind to the receptors. Cannabinoids come from three different places: 

•     Endocannabinoids – these are produced by the body on demand, usually in tesponse to injury; five different endocannabinoids have been identified, including anandamide and 2-AG 
•     Synthetic cannabinoids – these are produced by scientists in a laboratory and  include dronabinol (Marinol) and nabilone       (Cesamet) 
•     Phytocannabinoids – these are produced by the cannabis plant; there are over 85 cannabinoids in the cannabis plant, including THC and cannabidiol as the main two

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” (located in 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.

A study using weakly radioactive THC-like synthetic drugs investigated where the human cannabinoid receptors were located. When people were given this radioactive drug and their brains were scanned, CB1 receptors were found all over the brain. The results showed that cannabinoid receptor binding sites in the human brain are localized mainly in: the forebrain areas associated with higher cognitive functions; the forebrain, midbrain and hindbrain areas associated with the control of movement; and in hindbrain areas associated with the control of motor and sensory functions of the autonomic nervous system. This is consistent with the fact that cannabis has many different effects on mental function.

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 and most synthetic cannabinoids do not have the same effects as the cannabinoids in the cannabis plant. Many researchers are concentrating on studying the endocannabinoids (the cannabinoids produced in the body), in order to understand why our bodies 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, those that are found in the cannabis plant; 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 on 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. For now, many patients are using natural cannabis for relief of conditions for which medications have not worked or have been too toxic.
References
Herkenham et al. Cannabinoid Receptor Localization in Brain. Proceedings of the National Academy of Sciences USA 87 (1990): 1932-36
 
Glass et al. Cannbinoid Receptors in the Human Brain: A Detailed Anatomical and Quantitative Autoradiographic Study in the Fetal, Neonatal and Adult Human Brain. Neuroscience 77 (1997): 299-318 

Marsicano et al. The Endogenous Cannabinoid System Controls Extinction of Aversive Memories. Nature 418 (2002): 530-34 
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CBD - Cannabidiol

Cannabidiol, the second most common cannabinoid in cannabis, is a non-psychoactive compound with many medicinal effects.  It has been shown in scientific studies to have potent anti-inflammatory effects, anti-convulsant properties, anti-anxiety effects, anti-psychotic effects, anti-spasmodic effects (stops spasms), and anti-emetic effects (stops vomiting). It also has been shown to inhibit tumor cell growth. 

CBD also appears to dampen down the psychoactive effects of THC, calming any uncomfortable anxiety or paranoia that THC can sometimes cause.  CBD also appears to decrease short-term memory loss that can occur with THC use and CBD can also decrease the hunger often associated with cannabis use.  CBD in low doses appears to be alerting and in high doses is sedating.  CBD has not been reported to have any negative side effects!  There appears to be no tolerance to the effects of CBD as it works differently than THC.
  
In California, medical cannabis that is available to approved qualifying medical cannabis patients contains mostly THC and very little CBD.  The THC levels are reported to range from 4% - 30%. The higher the percentage, the more the psychoactive effects.  Cannabidiol levels are reported to be <1% for almost all strains currently used by patients.  However, there are a number of CBD-rich strains (4% - 18%) available for patients to choose from - these strains are becoming more available and are currently available to be inhaled, taken under the tongue as a tincture, and there are even some edible products that contain CBD.  

The demand for strains with higher CBD is growing as more people learn about CBD and its medicinal benefits.  It is the trend for patients to seek out TESTED MEDICINE.  Tested medicine goes through a process in a laboratory wherein the potency levels of THC, CBD, and other cannabinoids are measured and reported - this is called the cannabinoid profile.  The medicine is also tested for pesticides, molds and bacteria.  It is a MUCH BETTER way to choose medicine - you can pick the levels of the cannabinoids depending on your symptoms so that you optimize your results.  And knowing that the medicine does not contain pesticides or contaminants is very reassuring.   

Choosing your medicine based on the designation of Sativa, Indica or Hybrid is only helpful to help decide daytime or nighttime use; it is better to choose medicine based on the cannabinoid profile. Tested cannabis allows for patients to have some control over the quality and content of the medicine and is now becoming more available.
References

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