Related Experiment Video
Updated: Aug 10, 2026

The Xenopus Oocyte Cut-open Vaseline Gap Voltage-clamp Technique With Fluorometry
Published on: March 11, 2014
Fluctuation analysis of sodium channels in epithelia
Abstract:
When compiling results obtained with various techniques, it appears that the apical Na translocators are channels of high Na, Li selectivity that permit large transport rates at low driving forces. The concentration dependence of the transport rate is linear at least up to 60 mM Nao. The voltage dependence is of the Goldman-Hodgkin-Katz type or closely related to it. Outward facing surface charges have little influence. The flux ratio exponent is close to unity, compatible with single-site channels or multisite channels of low occupancy. Noise analysis has proven particularly suited for following changes in the density of conducting channels in the living preparation, and has shown that cellular and hormonal regulatory mechanisms control Na transport by changing the channel density in a variety of ways.
More Related Videos
Related Concept Videos
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.
Patch Clamp
In this method, a glass micropipette containing electrolyte solution is tightly sealed against a small portion of the cell membrane. As a result, a patch of the cell...
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...
Electrochemical Gradient and Channel Proteins: An Overview
The electrical gradient: The electrical gradient across cell membranes refers to the difference in electric charge between the inside and outside of a cell. This difference drives the movement of ions towards or away from the cells. For instance, if the inside of the cell is more negatively charged relative to the...
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...

