| Autor: |
Nicole Schöbel, Debbie Radtke, Matthias Lübbert, Günter Gisselmann, Ramona Lehmann, Annika Cichy, Benjamin S P Schreiner, Janine Altmüller, Alan C Spector, Jennifer Spehr, Hanns Hatt, Christian H Wetzel |
| Jazyk: |
angličtina |
| Rok vydání: |
2012 |
| Předmět: |
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| Zdroj: |
PLoS ONE, Vol 7, Iss 11, p e48005 (2012) |
| Druh dokumentu: |
article |
| ISSN: |
1932-6203 |
| DOI: |
10.1371/journal.pone.0048005 |
| Popis: |
Intracellular Cl(-) concentrations ([Cl(-)](i)) of sensory neurons regulate signal transmission and signal amplification. In dorsal root ganglion (DRG) and olfactory sensory neurons (OSNs), Cl(-) is accumulated by the Na(+)-K(+)-2Cl(-) cotransporter 1 (NKCC1), resulting in a [Cl(-)](i) above electrochemical equilibrium and a depolarizing Cl(-) efflux upon Cl(-) channel opening. Here, we investigate the [Cl(-)](i) and function of Cl(-) in primary sensory neurons of trigeminal ganglia (TG) of wild type (WT) and NKCC1(-/-) mice using pharmacological and imaging approaches, patch-clamping, as well as behavioral testing. The [Cl(-)](i) of WT TG neurons indicated active NKCC1-dependent Cl(-) accumulation. Gamma-aminobutyric acid (GABA)(A) receptor activation induced a reduction of [Cl(-)](i) as well as Ca(2+) transients in a corresponding fraction of TG neurons. Ca(2+) transients were sensitive to inhibition of NKCC1 and voltage-gated Ca(2+) channels (VGCCs). Ca(2+) responses induced by capsaicin, a prototypical stimulus of transient receptor potential vanilloid subfamily member-1 (TRPV1) were diminished in NKCC1(-/-) TG neurons, but elevated under conditions of a lowered [Cl(-)](o) suggesting a Cl(-)-dependent amplification of capsaicin-induced responses. Using next generation sequencing (NGS), we found expression of different Ca(2+)-activated Cl(-) channels (CaCCs) in TGs of mice. Pharmacological inhibition of CaCCs reduced the amplitude of capsaicin-induced responses of TG neurons in Ca(2+) imaging and electrophysiological recordings. In a behavioral paradigm, NKCC1(-/-) mice showed less avoidance of the aversive stimulus capsaicin. In summary, our results strongly argue for a Ca(2+)-activated Cl(-)-dependent signal amplification mechanism in TG neurons that requires intracellular Cl(-) accumulation by NKCC1 and the activation of CaCCs. |
| Databáze: |
Directory of Open Access Journals |
| Externí odkaz: |
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