Cannabinoid Receptors: A Link Between Genetic Variations and Depression

Saturday, February 6th, 2010

A growing body of scientific research suggests that cannabinoid receptors or the endocannabinoid system may have a therapeutic role in major depression (MD) and/or bipolar disorder (BD). A paper published in “Pharmaceutic Research” demonstrated that certain variations or mutations associated with the Endocannabinoid system may make humans more susceptible to MD or BD. The current study found that specific mutations in both the CB1 receptor and FAAH enzyme, were found in human subjects suffering from MD and BP.  Interestingly, only the CB1 receptor mutations were linked to Major Depression, while both CB1 receptor and FAAH mutations were found patients suffering from bipolar disorders

What is the Endocannabinoid system (ECS)? And why is it linked to emotion?

The ECS is comprised of two receptors, the CB1 and CB2 receptor. The CB1 receptor is perhaps one of the most abundant receptors in the human brain. It is found in high amounts in many areas of the human brain, including parts of the brain important for emotion.  It is fairly common knowledge that THC, from the cannabis plant, can activate CB1 receptors. However, humans and many other animals also make a “natural THC” called Anandamide.  Anandamide is synthesized by cells in our body, and can impact a variety of natural processes such as eating, sleeping, memory, energy, and mood. Once Anandamide is synthesized it will be degraded or destroyed by another protein FAAH.  The enzyme activity or the rate at which FAAH destroys Anandamide will indirectly affect the level of CB1 activity.

So, if FAAH is over active there will be fewer signals in the brain telling you to eat and sleep, among other things.  If there is not enough FAAH, it will make a person hungry.

Mutations in FAAH or cannabinoid receptors may underlie many diseases; in fact a “Clinical Endocannabinoid Deficiency” has already been proposed to explain some chronic diseases such as “migraines, fibromyalgia, irritable bowel syndrome, and other functional conditions alleviated by clinical cannabis“. A previous study has also linked variations in FAAH and CB1 rceptors to anorexia nervosa and bulimia nervosa.

Acetaminophen Synergizes Through the CB1 Receptor

Sunday, January 3rd, 2010

Acetaminophen and cannabinoid receptor interactions were the focus of a research article published in the journal of Neuropharmacology in late December 2009. The research demonstrates that the effects of Acetaminophen on pain are mediated through the CB1 receptor. Acetaminophen has previously been shown to elevate the levels of endocannabinoids in the body. Thus increasing the amount of activated cannabinoid receptors, leading to pain relief and anti-inflammatory effects.

Most prescription narcotics such as percocet and vicodin are cut with acetaminophen by pharmaceutical companies. This gives the pain killers more of a “kick.” Without acetaminophen, some pain killers are not nearly as effective. Researchers have been investigating the molecular mechanism for this interaction and the Endocannabinoid System appears to be a big player. Previous research has also shown that there is some “cross talk” between opiate receptors and cannabinoid receptors.

The study investigated the effects of acetaminophen in combination with different pain killers. The authors found that a combination of acetaminophen with gabapentin or morphine produced synergistic pain killing effects in rats.  The results may have clinical significance because the effect was observed in rats that are a model of spinal cord injury. Interestingly, this synergistic pain relief disappeared when the rats were given AM251. AM251 blocks the Cannabinoid Type 1 Receptor (CB1R) thus inhibiting CB1R activation.

Given the notable toxicity of acetaminophen,  cannabinoids might be a reasonable supplement to accompany current treatments for pain.