Researchers at the University of Michigan Health System have discovered a link between the brain molecule glutamate, a neurotransmitter, and pain levels in fibromyalgia patients.

Researchers found that pain levels decreased when levels of glutamate went down. This discovery could lead to new drug therapies for treatment of fibromyalgia.

A neurotransmitter is a chemical in the brain that relays and amplifies information between neurons in the nervous system and other cells. When glutamate is released bya neuron, it attaches to receptors in the next neuron and causes that cell to become excited, or more active.

Glutamate was previously linked to fibromyalgia pain in studies that showed certain regions of the brain in fibromyalgia patients were highly excited. One of these regions is the insula.

In these previous studies, functional magnetic resonance imaging (fMRI) had shown higher levels of brain activity in the insula in fibromyalgia patients. This led researchers at the University of Michigan to theorize that there may be a relationship between the level glutamate in the insula and the higher levels of activity there.

To test their hypothesis, the researchers conducted clinical trials where fibromyalgia patients would receive acupuncture or sham acupuncture treatments. The sham acupuncture treatment was done using a sharp device to mimic real acupuncture. Proton magnetic resonance spectroscopy was performed before, and after 4 weeks of treatment to gauge the link between pain and glutamate.

After 4 weeks of treatment, both the real and sham acupuncture treatments resulted in significant reduction of pain. The reduction in pain for both groups was linked to lower levels of glutamate in the insula. Those patients that reported greater reductions in pain also showed greater reductions in levels of glutamate.

“If these findings are replicated, investigators performing clinical treatment trials in fibromyalgia could potentially use glutamate as a ’surrogate’ marker of disease response,” says lead author Richard E. Harris, Ph.D., research assistant professor in the Division of Rheumatology at the University of Michigan Medical School’s Department of Internal Medicine and a researcher at the University of Michigan Chronic Pain and Fatigue Research Center.

Dr. Harris also said that due to the small number of participants in this study further research was necessary.

The results of this study have been published in the current issue of the journal Arthritis and Rheumatism.