A New Approach to Differential Peripheral Nerve Fiber Block: Na+, K+-ATPase Inhibition

Differential block of peripheral nerve fibers was attempted in vitro by a new approach based on inhibiting the membrane pump with ouabain. Sequential concentration dependent extinction of the components of the compound action potential was obtained: C extinguished first, Aγ next, Aβ last. The sequence conforms to expectations based on axonal size.Because pain is mediated by C and Aγ fibers, and block of these groups by ouabain was not reversed readily, further investigation of the practicability of the new approach seems warranted.