On the resting potential of isolated frog sympathetic neurons

Neuron. 1989 Aug;3(2):153-61. doi: 10.1016/0896-6273(89)90028-7.


One of the oldest questions of electrophysiology, the origin of the resting potential, has yet to be answered satisfactorily for most cells. Isolated frog sympathetic neurons, studied with whole-cell recording, generally have resting potentials of approximately -75 mV with an input resistance of approximately 300 M omega. These properties are not expected from the M-type K+ current (IM) or from other ionic currents previously described in these cells. In the -60 to -110 M mV voltage region, at least three currents are present: an inwardly rectifying current (IQ), a resting current with little voltage sensitivity carried at least in part by K+, and a (Na+,K+)ATPase pump current. The resting K+ current, not IM or IQ is the primary ionic current near the resting potential under these conditions. The electrogenic pump contributes an additional approximately 10 mV of hyperpolarization.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Calcium / metabolism
  • Calcium / physiology
  • Cell Membrane Permeability / physiology
  • Cell Separation
  • Ganglia, Sympathetic / cytology
  • Ganglia, Sympathetic / metabolism
  • Ganglia, Sympathetic / physiology*
  • Membrane Potentials / physiology
  • Microelectrodes
  • Neurons / cytology
  • Neurons / metabolism
  • Neurons / physiology*
  • Potassium / metabolism
  • Potassium / physiology
  • Rana catesbeiana
  • Rana pipiens
  • Sodium-Potassium-Exchanging ATPase / physiology


  • Sodium-Potassium-Exchanging ATPase
  • Potassium
  • Calcium