Coronal forebrain sections of WT and Pax8-KO mice at P12 were immunostained with an antibody against PV that labels a subset of GABAergic interneurons. PV immunoreactivity was quantified on 3 consecutive sections from each animal using 4 animals per genotype and normalized to the respective cortical area. In saline-treated Pax8-KO mice, PV immunoreactivity was strongly reduced but could be partially restored upon TA3 treatment. Scale bar, 50 μm. **, P < .01; ***, P < .001. Abbreviation: AU, arbitrary unit.