Researchers at the University of Michigan Health System have found a key linkage between pain and a specific brain molecule, a discovery that lends new insight into fibromyalgia, an often-baffling chronic pain condition.
In patients with fibromyalgia, researchers found, pain decreased when levels of the brain molecule called glutamate went down. The results of this study, which appears in the journal Arthritis and Rheumatism, could be useful to researchers looking for new drugs that treat fibromyalgia, the authors say.
“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 U-M Medical School's Department of Internal Medicine and a researcher at the U-M Chronic Pain and Fatigue Research Center.
The molecule glutamate is a neurotransmitter, which means it conveys information between neurons in the nervous system. When glutamate is released from one neuron, it diffuses across the space between cells, and then binds to receptors on the next neuron in line and causes the cell to become excited, or to be more active.
This molecule was suspected to play a role in fibromyalgia because previous studies had shown that some brain regions in fibromyalgia patients appear to be highly excited. One such region is the insula.
In functional magnetic resonance imaging (fMRI) studies, researchers at U-M had previously shown that the insula displays augmented activity in fibromyalgia, which means neurons in these patients are more active in this part of the brain. The U-M team hypothesized, Harris notes, that more activity among these neurons might be related to the level of glutamate in this region.
To gauge the linkage between pain and glutamate, the researchers used a non-invasive brain imaging techinique called proton magnetic resonance spectroscopy (H-MRS). H-MRS was performed once before and once following a four-week course of acupuncture or “sham” acupuncture.
Researchers used either acupuncture or sham acupuncture to reduce pain symptoms. The sham procedure involved using a sharp device to prick the skin in order to mimic real acupuncture sensations.
Following the four weeks of treatment, both clinical and experimental pain reported were reduced significantly. More importantly the reduction in both pain outcomes was linked with reductions in glutamate levels in the insula: patients with greater reductions in pain showed greater reductions in glutamate. This suggests that glutamate may play a role in this disease and that it could potentially be used as a biomarker of disease severity.
Because of the small number of participants in this study, further research should be conducted to verify the role of glutamate in fibromyalgia, Harris says.
Source: University of Michigan
Related stories:
Study shows how 'horse tranquiliser' stops depression
Researchers have shown exactly how the anaesthetic ketamine helps depression with images that show the orbitofrontal cortex – the part of the brain that is overactive in depression – being ‘switched off’.
New brain cells implicated in machinery of cannabinoid signaling
The brain cells called astrocytes, and not just neurons, are sensitive to the substances called cannabinoids—the active chemicals in marijuana.
Autoantibodies and neuropsychiatric events in lupus
Systemic lupus erythematosus (SLE), commonly known as lupus, can affect nearly any part of the body, including the joints, skin, kidneys, heart, nervous system, and brain. Along with joint pain, muscle pain, unexplained fever, extreme fatigue, and skin rashes, neurologic and psychiatric events often accompany this autoimmune disease. Depending on the study, between 37 and 95 percent of SLE patients experience signs and symptoms of neuropsychiatric (NP) disease. Determining the correct attribution to NP events is a challenge when managing nervous system disease in individual SLE patients, as well as a critical factor in selecting the right treatment and evaluating progress. For guidance in these decisions, doctors need reliable biomarkers -- which, as dedicated researchers know, have proven difficult to find.
Researchers add to understanding of how brain cells communicate
An hour from now, will you remember reading this? It all depends on proteins in your brain called NMDA receptors, which allow your neurons to communicate with each other.
Scientists Solve Sour Taste Proteins
A team led by Duke University Medical Center researchers has discovered two proteins in the taste buds on the surface of the tongue that are responsible for detecting sour tastes.
Energy-saving bacteria resist antibiotics
Bacteria save energy by producing proteins that moonlight, having different roles at different times, which may also protect the microbes from being killed. The moonlighting activity of one enzyme from the tuberculosis bacterium makes it partially resistant to a family of broad-spectrum antibiotics, according to a paper published in the September issue of the journal
Microbiology.
The first autism disease genes
The autistic disorder was first described, more than sixty years ago, by Dr. Leo Kanner of the Johns Hopkins Hospital (USA), who created the new label 'early infantile autism'. At the same time an Austrian scientist, Dr. Hans Asperger, described a milder form of the disorder that became known as Asperger Syndrome, characterised by higher cognitive abilities and more normal language function. Today, both disorders are classified in the continuum of 'Pervasive Developmental Disorders' (PDD), more often referred to as Autism Spectrum Disorders (ASD).
Researchers find MSG use linked to obesity
People who use monosodium glutamate, or MSG, as a flavor enhancer in their food are more likely than people who don't use it to be overweight or obese even though they have the same amount of physical activity and total calorie intake, according to a University of North Carolina at Chapel Hill School of Public Health study published this month in the journal
Obesity.