Time-related effects of systemic finasteride (FIN, 100 mg/kg, IP) on extracellular concentrations of dopamine (DA) and 3,4-dihydroxyphenylacetic acid (DOPAC) in the nucleus accumbens shell of Sprague-Dawley rats. FIN was tested in combination with (A–B) D1 agonist SKF 82958 (1 mg/kg, SC); (C–D) D2 agonist sumanirole (SUM, 3 mg/kg, SC); (E–F) D3 agonist PD 128907 (0.1 mg/kg, IP). Arrows represent injection time of FIN or its vehicle (VEH) and the dopaminergic agonist or saline (SAL). The interval corresponding to PPI testing is indicated by a dotted bar alongside the time axis. Values are expressed as mean percent of the baseline (average values of the three first samples) ± S.E.M for each time point. N = 7–8/group. *, P<0.05 compared with baseline values; °°°, P<0.001 in comparison with VEH+PD 128907. Significant within-group (time-dependent) effects are not indicated. For further details, see text.