Expression of K2P channels in sensory and motor neurons of the autonomic nervous system

J Mol Neurosci. 2012 Sep;48(1):86-96. doi: 10.1007/s12031-012-9780-y. Epub 2012 Apr 29.

Abstract

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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Arabidopsis Proteins / metabolism
  • Autonomic Nervous System / cytology*
  • Autonomic Nervous System / physiology*
  • Cells, Cultured
  • Intramolecular Transferases / metabolism
  • Mice
  • Mice, Inbred Strains
  • Motor Neurons / cytology
  • Motor Neurons / physiology*
  • Nerve Tissue Proteins / genetics
  • Nerve Tissue Proteins / physiology
  • Nodose Ganglion / cytology
  • Nodose Ganglion / physiology
  • Patch-Clamp Techniques
  • Potassium Channels / genetics
  • Potassium Channels / physiology
  • Potassium Channels, Tandem Pore Domain / genetics
  • Potassium Channels, Tandem Pore Domain / physiology*
  • Reverse Transcriptase Polymerase Chain Reaction
  • Sensory Receptor Cells / cytology
  • Sensory Receptor Cells / physiology*
  • Superior Cervical Ganglion / cytology
  • Superior Cervical Ganglion / physiology

Substances

  • Arabidopsis Proteins
  • Kcnk10 protein, mouse
  • Kcnk4 protein, mouse
  • Kcnk5 protein, mouse
  • Nerve Tissue Proteins
  • Potassium Channels
  • Potassium Channels, Tandem Pore Domain
  • TASK3 protein, mouse
  • Trik protein, mouse
  • potassium channel protein TREK-1
  • potassium channel subfamily K member 3
  • Intramolecular Transferases
  • marneral synthase, Arabidopsis