(A) Diagram to illustrate the electrophysiological footprint of neuropathic pain seen in substantia gelatinosa following peripheral nerve injury (Biggs et al., 2010). (A) Diagram to illustrate the electrophysiological footprint of neuropathic pain seen in substantia gelatinosa following peripheral nerve injury (Biggs et al., 2010). Five cell types characterized by their firing pattern, tonic, delay, irregular, phasic, or transient (Balasubramanyan et al., 2006), are listed at the top of the scheme, and the frequencies and amplitudes of sEPSCs and mEPSCs are listed at the right of the scheme. Upward arrows in green-colored squares indicate a nerve injury–induced increase in each type of synaptic event in each neuron type. Downward arrows in red-colored squares indicate a nerve injury–induced decrease. nd = not determined; horizontal double-headed arrow indicates no change. (B) Similar presentation to show cell-type–specific effects of gabapentin in substantia gelatinosa of nerve-injured animals. (C) Superimposition of patterns from (A) and (B). Yellow shading represents phenomena that were affected in one way by nerve injury and the opposite direction by gabapentin. Sascha R. A. Alles, and Peter A. Smith Pharmacol Rev 2018;70:315-347 Copyright © 2018 by The Author(s)‏