Neuron subtype specification in Atoh1-induced neurons. (A): Atoh1-induced neurons derived from Atoh1-induced pluripotent stem cells were allowed to mature in vitro, and cells at differentiation day 36 were immunostained with antibodies detecting dopaminergic (TH), GABAergic (GAD67), serotonergic (serotonin), and glutamatergic (VGluT1) neuron subtypes. Cell nuclei were counterstained with DAPI. Scale bars = 50 μm. (B): Immunostained neurons from 10 random-selected microscopic fields were counted to calculate the percentage of TH+, GAD67+, serotonin+, and VGluT1+ cells over DAPI+ cells. The data represent means ± SEM. Abbreviations: DAPI, 4′,6-diamidino-2-phenylindole; N.D., not detected; TH, tyrosine hydroxylase; VGluT, vesicular glutamate transporter 1.