D1 agonist-induced suppression of whole-cell Na⁺ current in NAc neurons is not altered by repeated cocaine administration. The ability of the DA D1 receptor-selective agonist SKF 38393 (0.1–10 μm) to suppress whole-cell Na⁺ current was not significantly different (ANOVA) in NAc neurons recorded from cocaine-treated rats and saline-treated control rats. Sample sizes for the 0.1, 1.0, and 10.0 μm concentrations of SKF 38393 are 6, 6, and 5 for both control and cocaine groups. In addition, another group of 30 cocaine pretreated neurons were tested with 1.0 μm SKF 38393 and exhibited average inhibition of 27.2 ± 1.7%, a value that is not significantly different from that obtained in 33 untreated neurons (24.5 ± 2.1%), as described in Figure 2 legend (t test).