Effects of Various Antiepileptics Used to Alleviate Neuropathic Pain on Compound Action Potential in Frog Sciatic Nerves: Comparison with Those of Local Anesthetics
Figure 1
Effect of lamotrigine (LTG) on compound action potentials (CAPs) recorded from frog sciatic nerve fibers. (a) The chemical structure of LTG. (b) Recordings of CAPs before (control), at 20 min after exposure to LTG, and thereafter 30 min in the absence of LTG. (c) Average time courses of changes in CAP peak amplitude following exposure to LTG at 0.02–0.5 mM for 20 min, relative to those before the soaking (each point: ). Relative CAP amplitude after washout of LTG is shown only for data at 0.5 mM. In this and subsequent figures, each point with vertical bars represents the mean and SEM. If the SEM of the values is smaller than the size of the symbol, the vertical bar is not shown. (d) The CAP inhibition produced by LTG is concentration dependent. The peak amplitudes of CAPs recorded from sciatic nerve fibers treated with LTG at various concentrations for 20 min, relative to control, which were plotted against LTG concentration (each point: ). This concentration-response curve was drawn according to the Hill equation (half-maximal inhibitory concentration (IC50) 0.44 mM; Hill coefficient ).
