Effects of glutaraldehyde on sodium channel activation and inactivation in frog nerve fiber

The effects of glutaraldehyde on sodium channel gating were investigated in the membrane of the node of Ranvier in frog nerve fiber. It was found that treating the membrane with glutaraldehyde slows the rate of inactivation, renders the inactivation curve considerably less steep, and leads to the appearance of a steady-state current component. It also decelerated the activation rate and reduced the slope of the central portion of the activation curve, which was shifted over to depolarization at the membrane. This produced no significant change in the effective charge in the effective charge of activation as determined from the limiting logarithmic slope of the activation curve. The mechanisms possibly underlying these changes in sodium channel gating are discussed.