Excitability of squid giant axons in the absence of univalent cations in the external medium.

Abstract

Under continuous intracellular perfusion with a dilute CsF (or Cs-phosphate) solution, squid [Loligo pealii] giant axons immersed in media containing only salts of divalent cations were found to maintain their ability to produce all-or-none action potentials. The experimental results are interpreted in terms of 2 stable conformations for the membrane macromolecules, and support the two-stable-states theory of excitation.