Effects of Various Antiepileptics Used to Alleviate Neuropathic Pain on Compound Action Potential in Frog Sciatic Nerves: Comparison with Those of Local Anesthetics
Figure 4
Effects of phenytoin (PHT), gabapentin, topiramate, and sodium valproate on CAPs recorded from frog sciatic nerve fibers. (a) The chemical structures of PHT, gabapentin, topiramate, and sodium valproate. (b) PHT minimally inhibits CAPs in a partially reversible manner. ((b)(A)) Recordings of CAPs before, at 20 min after exposure to PHT, and thereafter 30 min in the absence of PHT. ((b)(B)) The peak amplitudes of CAPs recorded from sciatic nerve fibers treated with PHT at various concentrations for 20 min, relative to control, which were plotted against PHT concentration (each point: –7). The line was arbitrarily drawn. ((c), (d), and (e)) Recordings of CAPs before and at 20 min after exposure to gabapentin (c), topiramate (d), and sodium valproate (e). They hardly affected CAPs.
