Article by Peter Chen, Lift News
The medicinal properties of cannabis have been spread widely in the form of personal anecdotes and online videos showcasing the wonders of CBD oil on seizure-ridden patients. These are compelling evidence for the medicinal benefits of cannabis; however, researchers such as Dr. Linda Parker, are still in search of empirical evidence and a deeper understanding of the biological pathways and mechanisms governing these claims.
Dr. Linda Parker is a psychology and neuroscience professor at the University of Guelph and has been studying the pharmacological properties of cannabinoids on brain behaviours for almost two decades. She is the current president of the CCIC and is the 2016 recipient of the ICRS Lifetime Achievement Award. She recently wrote a book titled Cannabinoids and the Brain where she discusses the history of cannabis research and references key findings relating to cannabinoids and the regulation of emotions, psychosis, learning and memory, reward and addiction, obesity and appetite, nausea, pain, epilepsy and neurodegenerative disorders.
She began studying cannabinoids in 1999. After publishing her seminal paper on the effects of ∆9-tetrahydrocannabinol (THC) in reducing nausea using a rat model, she received a letter from Professor Raphael Mechoulam who famously discovered THC in 1964. This prompted Dr. Parker to begin exploring the endocannabinoid system and undertake the search for naturally occurring cannabinoids. These endogenous cannabinoids were only discovered in the 1990s and their respective cannabinoid receptors (CB1 and CB2) were found in the late 1980s and early 1990s. Dr. Parker explains, “these CB1 receptors are the most prevalent receptor in the brain. They’re everywhere in the brain. So, when you take THC, it acts on all of these receptors in the area of learning and memory, anxiety, fear, nausea, pain…it’s acting on all of these receptors.”
Her research lab at the University of Guelph includes Dr. Cheryl Limebeer and Dr. Erin Rock, and together, they have worked extensively on the role of endocannabinoids in regulating specific local CB1 receptors to provide targeted therapeutic effects. She explains using nausea as an example: “When you give a drug that blocks enzymes responsible for deactivating natural endocannabinoid production, you in turn elevate the natural endocannabinoids only where they are produced. So, if you’re feeling nauseated, a natural endocannabinoid known as 2-AG is elevated only on the insular cortex and not on the part of your brain responsible for memory and learning, or anxiety, and you are left with no side effects. 2-AG will then act on the local CB1 receptor to reduce the levels of serotonin, which we have found to be responsible for nausea.”
Typically, endocannabinoids are only produced when and where they are needed, and production is regulated by the presence of certain enzymes. Dr. Parker has been working on enzyme-inhibitors that allow for the extended production of endocannabinoids for up to 24 hours. Studies have now shown that the continued release of endocannabinoids offers several therapeutic effects, including relief of pain, anxiety, depression and nausea.