Editing Resting potential (section)

== Measuring resting potentials ==
In some cells, the membrane potential is always changing (such as [[Cardiac pacemaker|cardiac pacemaker cells]]). For such cells there is never any "rest" and the "resting potential" is a theoretical concept. Other cells with little in the way of membrane transport functions that change with time have a resting membrane potential that can be measured by inserting an electrode into the cell.<ref name="electrode">An illustrated example of measuring membrane potentials with electrodes is in Figure 2.1 of ''Neuroscience'' by Dale Purves, et al. (see reference #1, above).</ref> Transmembrane potentials can also be measured optically with dyes that change their optical properties according to the membrane potential.{{cn|date=May 2025}}