Effects of finasteride (FIN, 100 mg/kg, IP) on the changes in acoustic startle and prepulse inhibition (PPI) induced by (A–B) the non-selective D1–D2 receptor agonist apomorphine (APO, 0.25 mg/kg, SC), (C–D) the D2-like receptor agonist quinpirole (QUI, 0.6 mg/kg, SC), (E–F) the D2 selective agonist sumanirole (SUM, 3 mg/kg, SC) in male Sprague-Dawley rats. Values represent mean ± SEM for each experimental group. N = 8–10/group. SAL, saline; VEH, vehicle of finasteride; *, P<0.05; **, P<0.01; ***, P<0.001 for comparisons indicated by dotted lines. Curvy brackets are used to indicate main effects. For more details, see text.