when the cell is at rest
At rest, the membrane potential is -60 millivolts (mV), which means that the inside of the cell is negative in comparison to the outside. This is ultimately due to an unequal distribution of ions, especially sodium and potassium, between the outside and inside of the cell (see Table 1).t rest, neurons (and most other cells, too) exhibit an electrical charge difference across the membrane. This difference, or membrane potential, can be measured with tiny electrodes connected to a voltmeter or an oscilloscope.
Cell Membrane Potentials. Cell membranes in general, and membranes of nerve cells in particular, maintain a small voltage or potential across the membrane in its normal or resting state. In the rest state, the inside of the nerve cell membrane is negative with respect to the outside (typically about -70 millivolts).The voltage arises from differences in concentration of the electrolyte ions K + and Na + .n the selectively permeable cell membranes are ion channels which allow K + ions to pass to the interior of the cell, but block Na + ions. Negatively charged proteins on the interior of the cell are also denied passage across the membrane.