Membrane properties of isolated mudpuppy taste cells

J Gen Physiol. 1988 Mar;91(3):351-71. doi: 10.1085/jgp.91.3.351.


The voltage-dependent currents of isolated Necturus lingual cells were studied using the whole-cell configuration of the patch-clamp technique. Nongustatory surface epithelial cells had only passive membrane properties. Small, spherical cells resembling basal cells responded to depolarizing voltage steps with predominantly outward K+ currents. Taste receptor cells generated both outward and inward currents in response to depolarizing voltage steps. Outward K+ currents activated at approximately 0 mV and increased almost linearly with increasing depolarization. The K+ current did not inactivate and was partially Ca++ dependent. One inward current activated at -40 mV, reached a peak at -20 mV, and rapidly inactivated. This transient inward current was blocked by tetrodotoxin (TTX), which indicates that it is an Na+ current. The other inward current activated at 0 mV, peaked at 30 mV, and slowly inactivated. This more sustained inward current had the kinetic and pharmacological properties of a slow Ca++ current. In addition, most taste cells had inwardly rectifying K+ currents. Sour taste stimuli (weak acids) decreased outward K+ currents and slightly reduced inward currents; bitter taste stimuli (quinine) reduced inward currents to a greater extent than outward currents. It is concluded that sour and bitter taste stimuli produce depolarizing receptor potentials, at least in part, by reducing the voltage-dependent K+ conductance.

Publication types

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

MeSH terms

  • Action Potentials
  • Animals
  • Calcium / metabolism
  • Electric Conductivity
  • In Vitro Techniques
  • Ion Channels / metabolism*
  • Membrane Potentials
  • Necturus / metabolism*
  • Potassium / metabolism
  • Sodium / metabolism
  • Taste / physiology
  • Taste Buds / metabolism*


  • Ion Channels
  • Sodium
  • Potassium
  • Calcium