@article{KollertDombertDoeringetal.2015, author = {Kollert, Sina and Dombert, Benjamin and D{\"o}ring, Frank and Wischmeyer, Erhard}, title = {Activation of TRESK channels by the inflammatory mediator lysophosphatidic acid balances nociceptive signalling}, series = {Scientific Reports}, volume = {5}, journal = {Scientific Reports}, number = {12548}, doi = {10.1038/srep12548}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-148312}, year = {2015}, abstract = {In dorsal root ganglia (DRG) neurons TRESK channels constitute a major current component of the standing outward current IK\(_{SO}\). A prominent physiological role of TRESK has been attributed to pain sensation. During inflammation mediators of pain e.g. lysophosphatidic acid (LPA) are released and modulate nociception. We demonstrate co-expression of TRESK and LPA receptors in DRG neurons. Heterologous expression of TRESK and LPA receptors in Xenopus oocytes revealed augmentation of basal K\(^{+}\) currents upon LPA application. In DRG neurons nociception can result from TRPV\(_{1}\) activation by capsaicin or LPA. Upon co-expression in Xenopus oocytes LPA simultaneously increased both depolarising TRPV\(_{1}\) and hyperpolarising TRESK currents. Patch-clamp recordings in cultured DRG neurons from TRESK[wt] mice displayed increased IK\(_{SO}\) after application of LPA whereas under these conditions IK\(_{SO}\) in neurons from TRESK[ko] mice remained unaltered. Under current-clamp conditions LPA application differentially modulated excitability in these genotypes upon depolarising pulses. Spike frequency was attenuated in TRESK[wt] neurons and, in contrast, augmented in TRESK[ko] neurons. Accordingly, excitation of nociceptive neurons by LPA is balanced by co-activation of TRESK channels. Hence excitation of sensory neurons is strongly controlled by the activity of TRESK channels, which therefore are good candidates for the treatment of pain disorders.}, language = {en} } @article{UeceylerSchliesserEvdokimovetal.2022, author = {{\"U}{\c{c}}eyler, Nurcan and Schließer, Mira and Evdokimov, Dimitar and Radziwon, Jakub and Feulner, Betty and Unterecker, Stefan and Rimmele, Florian and Walter, Uwe}, title = {Reduced midbrain raphe echogenicity in patients with fibromyalgia syndrome}, series = {PloS One}, volume = {17}, journal = {PloS One}, number = {11}, doi = {10.1371/journal.pone.0277316}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-300639}, year = {2022}, abstract = {Objectives The pathogenesis of fibromyalgia syndrome (FMS) is unclear. Transcranial ultrasonography revealed anechoic alteration of midbrain raphe in depression and anxiety disorders, suggesting affection of the central serotonergic system. Here, we assessed midbrain raphe echogenicity in FMS. Methods Sixty-six patients underwent transcranial sonography, of whom 53 were patients with FMS (27 women, 26 men), 13 patients with major depression and physical pain (all women), and 14 healthy controls (11 women, 3 men). Raphe echogenicity was graded visually as normal or hypoechogenic, and quantified by digitized image analysis, each by investigators blinded to the clinical diagnosis. Results Quantitative midbrain raphe echogenicity was lower in patients with FMS compared to healthy controls (p<0.05), but not different from that of patients with depression and accompanying physical pain. Pain and FMS symptom burden did not correlate with midbrain raphe echogenicity as well as the presence and severity of depressive symptoms. Conclusion We found reduced echogenicity of the midbrain raphe area in patients with FMS and in patients with depression and physical pain, independent of the presence or severity of pain, FMS, and depressive symptoms. Further exploration of this sonographic finding is necessary before this objective technique may enter diagnostic algorithms in FMS and depression.}, language = {en} }