Psychomotor sensitization and firing rate depression are occluded in T286D mice but rescued upon transgene inactivation. A, Psychomotor sensitization to cocaine is absent in T286D mice (WT SAL, n = 4; T286D SAL, n = 4; WT COC, n = 6; T286D COC, n = 6). B, Sample traces from T286D SAL and T286D COC at 120, 160, and 200 pA. C, A sensitizing regimen of cocaine (5 × 15 mg/kg) does not further decrease the firing rate depression in T286D mice (SAL, n = 14; COC, n = 21). D, Sample traces from T286D ON (transgene turned on) and T286D OFF (transgene turned off) at 100, 140, and 180 pA. E, Turning the transgene OFF re-establishes a normal firing rate. Inset, no differences in steady-state voltage responses to a series of current pulses between T286 ON (n = 9) and T286 OFF (n = 8). F, Turning the transgene OFF readjusts the A-type K+ current-regulated intrinsic excitability parameters, the latency to the first spike and interspike interval (at 160 pA; T286D ON, n = 9 cells; T286 OFF, n = 8 cells). G, Turning the transgene OFF rescues the psychomotor sensitization phenotype (T286D OFF SAL, n = 9; T286 OFF COC, n = 14). Calibration: 200 ms, 50 mV. Error bars indicate SEM. *p < 0.05.