Functional study of endothelin B receptors in satellite glial cells in trigeminal ganglia

There is immunohistochemical evidence for endothelin ( ET) receptors in satellite glial cells in sensory ganglia, but there is no information on the function of these receptors. We used calcium imaging to study this question in isolated mouse trigeminal ganglia and found that satellite glial cells are highly sensitive to ET-1, with threshold at 0.05 nM. Responses displayed strong desensitization at ET-1 concentrations of more than 1 nM. A large component of the response persisted when Ca2+ was deleted from the external medium, consistent with Ca2+ release from internal stores. The use of receptor selective agents showed that the responses were mediated by ETB receptors. We conclude that satellite glial cells display endothelin receptors, which may participate in neuron-glia communications in the trigeminal ganglia. NeuroReport 22:465-469 (C) 2011 Wolters Kluwer Health vertical bar Lippincott Williams & Wilkins.