14 DAY TRIAL // Marijuana has over recent years been advocated as one of the ways people suffering from chronic diseases could keep their pain under control, and has as such been prescribed by doctors to their patients. But a new scientific study comes to show that a class of chemicals found in cannabinoids, the active ingredient in the plant, could in fact be helping pain spread and endure, rather than reduce and calm it. The research comes from experts at the University of Texas Medical Branch in Galveston.
According to a new paper, published in the latest issue of the respected journal Science, it may be that the class of compounds known as “endocannabinoids,” which are in fact produced in the human body, may be the triggers that allow pain to endure rather than fading away. The researchers give the example of a person hammering a nail in, who strikes their own finger. After a brief moment of intense pain, a few minutes go by, and they are able to go back to their job. The thinking goes that, if marijuana is involved, the pain would last longer.
“In the spinal cord there's a balance of systems that control what information, including information about pain, is transmitted to the brain. Excitatory systems act like a car's accelerator, and inhibitory ones act like the brakes. What we found is that in the spinal cord endocannabinoids can disable the brakes,” explains UTMB professor Volker Neugebauer, who was also one of the authors of the Science paper. Other collaborators and authors include UTMB senior research scientist Guangchen Ji and colleagues from research institutes and universities in Switzerland, Hungary, Japan, Venezuela, France and Germany.
In the new experiments, the researchers used mouse spinal cord slices filled with inhibitory neurons, which stop signals associated with pain, for instance. On them, the team applied biochemical mimics of endocannabinoid compounds, and noticed that their activity stopped. When they used spinal slices which had been engineered to lack endocannabinoid receptors, the reactions appeared as normal. Their work was further proven by using electron microscopy, which proved the receptors for the chemicals were on the inhibitory neurons, and not on the excitatory ones.
“To sum up, we've discovered a novel mechanism that can transform transient normal pain into persistent chronic pain. Persistent pain is notoriously difficult to treat, and this study offers insight into new mechanisms and possibly a new target in the spinal cord,” concludes Neugebauer, quoted by e!Science News.