Fig. 1

The schematic graphic displays how cells regulate transmembrane potential. Most cells maintain a transmembrane potential with the interior negatively charged relative to the exterior. When cell membrane receptors facilitate the influx of anions or efflux of cations, intracellular charge becomes more negative, a phenomenon referred to as hyperpolarization. Conversely, when anions efflux or cations influx, intracellular charge shifts towards less negative or even positive, termed depolarization