Transient changes in electrical potential differences across frog skin

Abstract

The time course of changes in potential difference across frog skin (Rana pipiens) following rapid changes in composition of the bathing solutions has been investigated. Increasing Na concentration in the outside solution results in a rapid rise in potential difference which is nearly complete in 0.4–0.5 sec. Analysis of the time course of this change strongly suggests the presence of a barrier to Na movement located quite near the anatomical outside of the skin. The change in potential difference following changes in the K concentration of the inside solution is much slower, and is consistent with the location of the K-sensitive barrier 150–250 µ from the inner surface of the skin.