Inwardly rectifying potassium channel Kir4.1 is responsible for the native inward potassium conductance of satellite glial cells in sensory ganglia

X. Tang, T. M. Schmidt, C. E. Perez-Leighton, P. Kofuji*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

37 Scopus citations

Abstract

Satellite glial cells (SGCs) surround primary afferent neurons in sensory ganglia, and increasing evidence has implicated the K+ channels of SGCs in affecting or regulating sensory ganglion excitability. The inwardly rectifying K+ (Kir) channel Kir4.1 is highly expressed in several types of glial cells in the central nervous system (CNS) where it has been implicated in extracellular K+ concentration buffering. Upon neuronal activity, the extracellular K+ concentration increases, and if not corrected, causes neuronal depolarization and uncontrolled changes in neuronal excitability. Recently, it has been demonstrated that knockdown of Kir4.1 expression in trigeminal ganglia leads to neuronal hyperexcitability in this ganglia and heightened nociception. Thus, we investigated the contribution of Kir4.1 to the membrane K+ conductance of SGCs in neonatal and adult mouse trigeminal and dorsal root ganglia. Whole cell patch clamp recordings were performed in conjunction with immunocytochemistry and quantitative transcript analysis in various mouse lines. We found that in wild-type mice, the inward K+ conductance of SGCs is blocked almost completely with extracellular barium, cesium and desipramine, consistent with a conductance mediated by Kir channels. We then utilized mouse lines in which genetic ablation led to partial or complete loss of Kir4.1 expression to assess the role of this channel subunit in SGCs. The inward K+ currents of SGCs in Kir4.1+/- mice were decreased by about half while these currents were almost completely absent in Kir4.1-/- mice. These findings in combination with previous reports support the notion that Kir4.1 is the principal Kir channel type in SGCs. Therefore Kir4.1 emerges as a key regulator of SGC function and possibly neuronal excitability in sensory ganglia.

Original languageEnglish (US)
Pages (from-to)397-407
Number of pages11
JournalNeuroscience
Volume166
Issue number2
DOIs
StatePublished - Mar 17 2010

Keywords

  • Dorsal root ganglia
  • KCNJ10
  • Pain
  • Potassium buffering
  • Potassium channel
  • Trigeminal ganglia

ASJC Scopus subject areas

  • Neuroscience(all)

Fingerprint Dive into the research topics of 'Inwardly rectifying potassium channel Kir4.1 is responsible for the native inward potassium conductance of satellite glial cells in sensory ganglia'. Together they form a unique fingerprint.

Cite this