What is Parkinson’s disease?
Parkinson’s disease (PD) is a neurodegenerative disorder that affects roughly 1 million Americans. There is no known cause or cure for Parkinson’s, and it most often occurs after the age of 60. Symptoms include tremors, loss of motor control, and difficulty walking. Depression can also result from Parkinson’s.
PD involves the dysfunction and breakdown of dopamine-producing neurons in a part of the brain called the substantia nigra. This part of the brain produces the pleasure signaller dopamine and sends it to the various regions of the brain that use dopamine as a neurotransmitter. One of these regions is the motor cortex. It is unclear why, although the substantia nigra signals many parts of the brain, only the motor cortex is affected by the breakdown of its dopamine neurons.
Our muscles work in harmonious concert with one another to produce fine motor activity and small detailed movements. In general, there is a protagonist and antagonist muscle group for each action. For example, your bicep is the protagonist for lifting your hand to your shoulder, and your tricep is the antagonist. This principle carries over to your fingers and toes and eyes and even your abs. By firing both muscle groups at exactly the right ratio to one another, motion in a very specific controlled direction is possible.
The essential function of dopamine in this process is to reduce an inhibitory signal that blocks the antagonist muscle from firing too much. When this inhibition is inhibited, the two opposing muscles fall out of sync with one another and the tremors associated with PD occur.
Can CBD relieve the symptoms of Parkinson’s?
As we discuss in this article about the brain, CBD is a very active molecule in both the brain and the rest of the body. The function of the endocannabinoid system in regulating and balancing all of the other cellular processes is becoming clearer and clearer, and when deficiencies in this system occur, CBD and plant cannabinoids can be used to treat them.
In Parkinson’s, the substantia nigra loses from 50-80% of its neurons before symptoms occur. This is thanks to an evolutionary trick your brain picked up somewhere in the last 3 million years called plasticity. Plasticity is the ability of neurons to rewire themselves in the case of damage or disease. CBD and phytocannabinoid-rich mixtures are powerful in promoting neuroplasticity by augmenting (adding to) the activity of the endocannabinoid system. The endocannabinoid anandamide is a key player in the rerouting of neural pathways.
Middle to late stages
In latin, substantia nigra means “black substance”. This part of the brain is so named because there are black pigments in the dopaminergic neurons found here that cause it to have a darker color than the surrounding brain tissue. This pigment also binds to and collects proteins that are produced only in these specific cells as part of the dopamine pathway.
This build-up is presumed to be one of the causes of the death of cells in this part of the brain, as the plaque that it forms is both toxic and physically obstructive of the function of the neuron. CBD along with CBC (cannabichromene) and CBG (cannabigerol) are known antioxidants, and oxidation of microtubule structures is what leads to the free-floating proteins that constitute the plaque. This explains part of the correlation between CBD use and slowed progression of symptoms.
As the disease progresses, psychological symptoms are sure to materialize. Depression and anxiety are common and they can significantly impede the maintenance of this disease. The ability of CBD to relieve these mental roadblocks should not be underestimated when considering its therapeutic potential for patients of Parkinson’s disease.