Potassium effect on the electrophysiological properties of the giant nerve cell bodies of Arion subfuscus (gastropoda:pulmonata)

The effect of the extracellular potassium concentration [Ko+] on the membrane and action potentials of Arion subfuscus subesophageal ganglion has been investigated. 2. An increase in [Ko+] depolarizes cellular membrane as in many other preparations. 3. A ten-fold change in [Ko+] results in a 29.4 mV change in the resting potential. 4. A modified constant field equation account for the behaviour of the resting potentials that differ considerably from the Nernst equation. 5. Mean values of internal potassium concentration [Ki+] and PNa/PK were determined. 6. Changes in frequency and shape of action potentials of spontaneous discharging neurons were observed when exposed to a high [Ko+].