Extracellular Potassium Experiment

In order to determine the extent to which the reversal potential for potassium determines the resting membrane potential of a given cell, a mechanism is needed to determine the change in membrane voltage across the cell in different extracellular potassium solutions. The intracellular recording technique consists of puncturing a prepared cell with a conductive pipette. The difference in potential between the extracellular electrode and the wire in the pipette is recorded and displayed on the voltage vs. time graph. Figure 1 provides an example of an intracellular voltage recording trace for a muscle fiber cell. The dip in the voltage graph occurs after the insertion of the pipette into the cell and reflects the resting membrane voltage of the …show more content…
These results support the findings of the current study, in which the manipulation of extracellular potassium concentrations changed the membrane potential and that this membrane potential may be affected by the permeability of other ions besides …show more content…
Dulhunty (1977) also found that the extracellular potassium and chloride concentrations could affect the membrane potential in such a way that could be modelled by the GHK equation, depending on the concentration of chloride intracellularly. These results also support the hypothesis and results that the GHK equation, which accounts for the permeability and concentration of several ions across the membrane, may provide a good model for predicting the membrane potential