Effect of central 5-HT_2C receptor blockade on 5-HT_2C receptor ligands mediated responses on DA release in vivo. Reversal by SB 242084 (1 mg/kg) of the DA effects elicited by 5 mg/kg SB 206553 (inverse agonist) (a, b) and 3 mg/kg Ro-60–0175 (agonist) (c, d) in the striatum and the nucleus accumbens. SB 242084 (SB242) was administered 30 min before SB 206553 (SB206) or Ro-60–0175 (Ro) as indicated by vertical arrows. Data represent mean ± SEM percentages of baseline in each sample (time courses) or averaged over 2 hr monitoring (insets) (n = 6–9 animals/group). *p < 0.05, **p < 0.01, and ***p < 0.001 versus the vehicle–vehicle (v/v) group and ⁺p < 0.05, ⁺⁺p < 0.01, and ⁺⁺⁺p < 0.001 versus the v/SB 206553 or v/Ro-60–0175 groups (Fisher's PLSD test).