A negative side effect of many Parkinson medications is the development of uncontrollable jerky movements known as dyskinesia.
A new line of research seeks to develop an effective medication that does not have the disconcerting side effects.
Neuroscience researcher Daniella Rylander studied two different systems in the brain that are believed to play an important role in the development of the side effects — glutamate and serotonin.
An overactivation of glutamate signals, caused by treatment with levodopa (the primary medication used for Parkinsonâ€™s), probably contributes to the development of dyskinesia.
Rylander’s research focuses on blocking this undesirable overactivation. “The receptor cells have different receptors on their surface where the glutamate is taken in to activate the cell. It is these receptors that I have tried to block. If we could find the right channel and subdue it then we could get more effective treatment with levodopa without any side effects. This has always been my goal.”
Tests in animal models, including rats, have shown very good results for the new method. A drug that blocks glutamate overactivation via the glutamate receptor ‘mGluR5’ was used in the study.
This has previously been tested on humans and so provides a head start in the time-consuming clinical trials required before a new drug can be introduced.
Serotonin also plays an important role in the development of dyskinesia in Parkinson’s disease.
“We have now shown for the first time that individuals who have a particularly large amount of a certain type of fibre on their serotonin cells are also at greater risk of being affected by dyskinesia after levodopa treatment,” says Rylander.
The new finding of a clear pathological change in the serotonin system can now be utilized to better tailor the individual treatment of patients with Parkinson’s disease.
Source: Lund University