Making, Testing, and Using Potassium Ion Selective Microelectrodes in Tissue Slices of Adult Brain

Potassium ions contribute to the resting membrane potential of cells and extracellular K⁺ concentration is a crucial regulator of cellular excitability. We describe how to make, calibrate and use monopolar K⁺-selective microelectrodes. Using such electrodes enables the measurement of electrically evoked K⁺ concentration dynamics in adult hippocampal slices.