Related Experiment Video
Updated: Aug 4, 2026

Patch Clamp and Perfusion Techniques for Studying Ion Channels Expressed in Xenopus oocytes
Published on: January 10, 2011
Potassium channels activated by sodium
1Department of Physiology, University of Colorado School of Medicine, Denver 80262.
Abstract:
Na+-activated K+ currents have been reported in snail neurones, crayfish giant motoneurones, cardiac myocytes, and in ganglion cells and brain stem cells from chick embryos. Such currents are seen in voltage-clamp experiments, following depolarization-induced Na+ influx. A variety of experiments have shown that the currents through the conductance pathways are indeed carried by K+ ions and that they are quantitatively dependent upon Na+ influx into the cells. Theoretical calculations indicate that such currents must make a substantial contribution to action potential repolarization. The conductances are activated by Li+ in invertebrate neurones, but not in the embryonic vertebrate neurones. Single-channel recordings from vertebrate brain stem cells reveal channels with conductances of about 50 pS, activated by Na+ concentrations in the 10-100 mM range.
Related Concept Videos
Action Potentials
Non-gated Ion Channels
Compared to the gated ion channels, the non-gated channels, also known as leakage or passive channels, have no gating mechanism.
The Role of Ion Channels in Neuronal Computation
Sometimes a single EPSP is strong enough to induce an action potential in the postsynaptic neuron. However, multiple presynaptic inputs must often create EPSPs around the same time for the postsynaptic neuron to be sufficiently depolarized to fire an action potential.
Voltage-gated Ion Channels
Generally, all voltage-gated ion channels have a 'voltage-sensing domain' that spans the lipid bilayer. The charged residues in the sensor move in response to the membrane potential changes that open the channel allowing ions movement. There are several types of...
Non-gated Ion Channels
Compared to the gated ion channels, the non-gated channels, also known as leakage or passive channels, have no gating mechanism.
Voltage-gated Ion Channels
Generally, all voltage-gated ion channels have a 'voltage-sensing domain' that spans the lipid bilayer. The charged residues in the sensor move in response to the membrane potential changes that open the channel allowing ions movement. There are several types of...

