Acute activation of rat dorsal root ganglion neurons and their satellite glial cells by the serum of patients suffering from fibromyalgia.

OBJECTIVES

The dorsal root ganglia (DRG) may play an important role in fibromyalgia pain. The DRG house the nucleus of somatosensory neurons carrying painful stimuli from different body parts. Each neuronal soma interacts with its enveloping immune-competent satellite glial cells (SGCs). Different mediators may activate SGCs, inducing stronger SGCs-neuron coupling and leading to chronic pain. Mice injected with immunoglobulin G of patients suffering from fibromyalgia develop hyperalgesia and neuropathy; in these instances, immunoglobulin G is deposited in DRG SGCs. Our aim was to determine whether the serum of women suffering from fibromyalgia induces more immediate stimulation of DRG neurons and/or their SGCs than does the serum of healthy women.

METHODS

Sera from 6 women suffering from fibromyalgia and from 6 healthy controls were tested on Wistar rat DRG neuron and SGCs primary cultures. Fluo-4 was used as intracellular calcium concentration reporter.

RESULTS

Among the 1477 DRG neurons studied, 625 were activated by human serum. Neuronal activation in patient serum was not different from that in control serum. A total of 558 SGCs were activated by human serum. Compared with that in control serum, a greater proportion of ATP-insensitive SGCs were stimulated by patients' serum (45% vs. 34%. Fisher's exact test, p=0.0092). Furthermore, patients' serum induced significantly greater SGCs calcium influx.

CONCLUSIONS

Serum of patients suffering from fibromyalgia induces more intense and widespread acute stimulation on ATP-insensitive SGCs. DRG SGCs may play a role in the pathogenesis of fibromyalgia.