A and B: locations of points in the thalamus at which antidromic activation was achieved using low-threshold (≤30 μA) current pulses. C: locations of points in C1 dorsal horn where examined trigeminothalamic tract (VcTT) neurons were recorded. 3V, third ventricle; APT, anterior pretectal nucleus; DDH, deep dorsal horn; MG, medial geniculate nucleus; ML, medial lemniscus; PF, parafascicular thalamic nucleus; PoM, posterior medial nucleus; PoT, posterior triangular nucleus; SDH, superficial dorsal horn; SN, substantia nigra; VPL, ventral posterior lateral nucleus; VPM, ventral posterior medical nucleus.