Effect of Sodium Lack on Local Response of the Single Crustacean Motor Axon

Summary

The local or initial response of crustacean single motor axons has been recorded at the stimulating cathode. The deflections caused by a short duration shock of positive and negative polarity are asymmetrical. Normally the deflection caused by the negative pulse is considerably larger. In the absence of sodium, with either dextrose or Choline Chloride substituted, the local potential disappears. The deflections caused by positive and negative pulses become symmetrical. The effect is instantaneous and reversible. It is concluded that the sodium ion is essential for the production of the local or initial response.