January 2010: Cannabinoids prevent and may aid in healing cell damage in multiple sclerosis. (Instituto Cajal, Madrid, Spain)

Cannabinoids prevent and may aid in healing cell damage in multiple sclerosis. (Instituto Cajal, Madrid, Spain)

First some background:
Multiple sclerosis is caused by cell damage in the brain and spinal cord, leading to a decreased ability of the body to communicate effectively with itself. One of the possible causes of multiple sclerosis is excitotoxicity mediated by AMPA glutamate receptors (see December 2009), but the root cause is the gradual damage and loss of the fatty myelin sheath surrounding specific areas of nerve cells. The myelin sheath is basically a layer of insulation which allows fast and precise electrical communication between cells within the brain and spinal cord.

The new information:
In mouse models of TMEV-IDD (Theiler’s murine encephalomyelitis virus-induced demyelinating disease) multiple sclerosis, increased cannabinoid levels led to protection against excitotoxicity, and thus protection against cell damage. In the experiment performed, an uptake blocker was introduced in order to increase the levels of cannabinoids at the junction between two cells. The increased level of cannabinoids led not only to the inhibition of excitotoxicity, but also activation of a factor within the cells which causes genetic changes. This factor is known as PPAR-gamma (peroxisome proliferator-activated receptor gamma), and it causes our DNA to tell the cell to produce more fat (recall that multiple sclerosis is caused by the destruction of the fatty insulation surrounding part of the nerve cell).

What this means:
Not only did this research provide more evidence that cannabinoids protect against neurodegenerative diseases, but that they may also aid in healing the cause of multiple sclerosis at a molecular level.

Loria, F, et al. “An endocannabinoid tone limits excitotoxicity in vitro and in a model of multiple sclerosis.” Neurobiology of disease. 37.1 (2010): 166-76.