Expression of K2P Channels in Sensory and Motor Neurons of the Autonomic Nervous System
- 726 Downloads
Several types of neurons within the central and peripheral somatic nervous system express two-pore-domain potassium (K2P) channels, providing them with resting potassium conductances. We demonstrate that these channels are also expressed in the autonomic nervous system where they might be important modulators of neuronal excitability. We observed strong mRNA expression of members of the TRESK and TREK subfamilies in both the mouse superior cervical ganglion (mSCG) and the mouse nodose ganglion (mNG). Motor mSCG neurons strongly expressed mRNA transcripts for TRESK and TREK-2 subunits, whereas TASK-1 and TASK-2 subunits were only moderately expressed, with only few or very few transcripts for TREK-1 and TRAAK (TRESK ≈ TREK-2 > TASK-2 ≈ TASK-1 > TREK-1 > TRAAK). Similarly, the TRESK and TREK-1 subunits were the most strongly expressed in sensorial mNG neurons, while TASK-1 and TASK-2 mRNAs were moderately expressed, and fewer TREK-2 and TRAAK transcripts were detected (TRESK ≈ TREK-1 > TASK-1 ≈ TASK-2 > TREK-2 > TRAAK). Moreover, cell-attached single-channel recordings showed a major contribution of TRESK and TREK-1 channels in mNG. As the level of TRESK mRNA expression was not statistically different between the ganglia analysed, the distinct expression of TREK-1 and TREK-2 subunits was the main difference observed between these structures. Our results strongly suggest that TRESK and TREK channels are important modulators of the sensorial and motor information flowing through the autonomic nervous system, probably exerting a strong influence on vagal reflexes.
KeywordsK2P channels Superior cervical ganglion Nodose ganglion Mouse Immunocytochemistry qRT-PCR Cell-attached patch Perforated patch
This work was supported by grants from the Spanish Government (MICINN BFU2008-02952/BFI and CONSOLIDER CSD2008-00005), the Galician Government (INBIOMED 2009/063) and the University of Vigo to JAL. SGIker technical and human support (UPV/EHU) is gratefully acknowledged. We also thank Vanesa Domínguez for her technical assistance.
- Karschin C, Wischmeyer E, Preisig-Muller R, Rajan S, Derst C, Grzeschik KH, Daut J, Karschin A (2001) Expression pattern in brain of TASK-1, TASK-3, and a tandem pore domain K+ channel subunit, TASK-5, associated with the central auditory nervous system. Mol Cell Neurosci 18:632–648PubMedCrossRefGoogle Scholar