Firing patterns of WT neurons and iN cells in the dorsal midbrain. Whole-cell recordings were performed on neurons in dorsal midbrain slices made from WT (A), Gad67–GFP (neurons expressing green fluorescence, putative GABAergic; B), and AAV–Ascl1/mCherry-infected mice at P12–P15 (30–49 DPI; young; C) or P60 (15–21 DPI; adult; D). Different categories of firing patterns of WT neurons were presented: classic regular-spiking (c-RS), instant regular-spiking (i-RS), classic non-accommodating (c-NAC), burst non-accommodating (b-NAC), delayed non-accommodating (d-NAC), accommodating (AC), classic stuttering (c-STUT), burst stuttering (b-STUT), and transient bursting (t-BST). Dash line denotes 0 mV. Calibration: 30 mV, 50 ms. E, Percentage of cells exhibiting different characteristic firing patterns recorded from neurons in WT mice (A), Gad67–GFP mice (B), and from iN cells induced in AAV–Ascl1/mCherry-infected mice at P12–P15 (C) or P60 (D).