Fig 4. Averaged actions of lidocaine (0.25 and 0.5% concentrations) on activity in four main classes of sensory and motor fibers. (A ) Time course of lidocaine, 0.25%, effects on “population” conduction in large sensory fibers (Aαβ, CAP data), small single sensory (Aδ) myelinated fibers (n = 27), C fibers (n = 22), and Aγ motor units (n = 23). Y-axis is the normalized area of CAP (for Aαβ fibers) or the percentage of unblocked fibers (relative to total number of fibers) against time after injection (t = 0). (B ) Time course of effects of lidocaine, 0.5%, on activity in large sensory fibers (Aαβ; n = 30), small sensory myelinated fibers (n = 32), C fibers (n = 33), and γ motor units (n = 15).