Neurotropin inhibits neuronal activity through potentiation of sustained Kv currents in primary cultured DRG neurons

J Pharmacol Sci. 2018 Jul;137(3):313-316. doi: 10.1016/j.jphs.2018.05.005. Epub 2018 May 31.

Abstract

Neurotropin (NTP) is a Japanese analgesic agent for treating neuropathic pain; however, its method of action remains unclear. This study examined the effects of NTP on the activity of small dorsal root ganglion (DRG) neurons using whole-cell patch clamp recordings. After 3 days of treatment, NTP decreased current injection-induced firing activity of cultured DRG neurons by raising the current threshold for action potential generation. Additionally, NTP increased the sustained component of voltage-gated potassium (Kv) channel currents without affecting other K+ currents. These results suggest that NTP inhibits the firing activity of DRG neurons through augmentation of sustained Kv current.

Keywords: DRG neuron; Neurotropin; Voltage-dependent K(+) channel.

MeSH terms

  • Action Potentials / drug effects
  • Analgesics / pharmacology*
  • Animals
  • Cells, Cultured
  • Ganglia, Spinal / cytology*
  • Male
  • Neurons / metabolism*
  • Patch-Clamp Techniques
  • Polysaccharides / pharmacology*
  • Potassium Channels, Voltage-Gated / metabolism*
  • Rats, Wistar
  • Time Factors

Substances

  • Analgesics
  • Polysaccharides
  • Potassium Channels, Voltage-Gated
  • neurotropin