Ionic Relations of Cells of Chara Australis V. The Action Potential

Abstract

The effect of various ions on the resting and action potential differences in single cells of the alga Ohara australis was studied. When the concentration of calcium ions in the external medium was changed by replacement with magnesium ions, keeping the total concentration constant, the peak level of the action potential changed reversibly. The change was about +29 mV per tenfold increase in calcium concentration, over a restricted range of the latter.