FIG. 7.

The relationship between stimulus intensity and corresponding compound action potential (CAP) amplitude with 100 μM 4-aminopyridine (4-AP) treatment. (A) Examples of individual CAP responses before and after 4-AP treatment. (B) Stimulus intensities ranged from 1.85 to 6.5 V. Application of 100 μM 4-AP significantly increased CAP amplitude at all stimulus intensities (*p < 0.05; n = 7). (C) Normalized CAP amplitude before 4-AP treatment (after recovery from compression) was plotted against the CAP amplitude after 4-AP treatment. All CAP amplitudes were normalized with respect to the maximum CAP value at peak stimulus (6.5 V). The linear relationship suggests 4-AP treatment had no bias in altering the conduction properties of large- or small-caliber axons.