Medical cannabis is a hotly debated topic. There is still much we don’t know about cannabis, but researchers from the Faculty of Health and Medical Sciences’ Department of Neuroscience have made a new discovery that could be critical to future medical cannabis research and treatment.
Cannabinoids are chemical compounds found in cannabis as well as the central nervous system. The researchers used a mouse model to show that a specific synthetic cannabinoid (cannabinoid WIN55,212-2) reduces essential tremor by activating spinal cord and brain support cells known as astrocytes. Previous research into medical cannabis has concentrated on nerve cells, or neurons.
“We concentrated on the disease essential tremor. It causes involuntary shaking, which can be extremely inhibiting and have a serious impact on the patient’s quality of life. However, the cannabinoid may have a beneficial effect on multiple sclerosis and spinal cord injuries, both of which cause involuntary shaking “According to the project’s leader, Associate Professor Jean-FranĂ§ois Perrier of the Department of Neuroscience.
“We discovered that injecting the cannabinoid WIN55,212-2 into the spinal cord activates the astrocytes and causes them to release the substance adenosine, which reduces nerve activity and thus the unwanted shaking.”
The discovery that astrocytes are involved in the explanation for cannabis’s effect is a completely novel approach to understanding cannabis’s medical effects, and it may help improve the treatment of patients suffering from involuntary shaking.
The spinal cord is in charge of the majority of our movements. When the motor neurons in the spinal cord are activated, both voluntary and spontaneous movements are elicited. Motor neurons connect the spinal cord to the muscles, and when a motor neuron sends an impulse to the muscles, it causes contraction and thus movement. When motor neurons send out conflicting signals at the same time, involuntary shaking occurs. That is why the researchers have concentrated their efforts on the spinal cord.
“One could imagine a new approach to medical cannabis for shaking, where youâ€”during the development of cannabis-based medicinal productsâ€”target the treatment either at the spinal cord or the astrocytesâ€”or, at best, the astrocytes of the spinal cord,” says Postdoc Eva Carlsen, who performed the majority of the tests during her Ph.D. and postdoc projects.
“By taking this approach, we will avoid affecting the neurons in the brain that are responsible for our memory and cognitive abilities, and we will be able to offer effective treatment to patients suffering from involuntary shaking without exposing them to any of the most problematic side effects of medical cannabis.”
The next step will be to conduct clinical trials on patients suffering from essential tremor to see if the new approach has the same effect in humans.
The study, titled Spinal astroglial cannabinoid receptors regulate pathological tremor, was published in the journal Nature Neuroscience.