a, Ankyrin G label after 12-14 DIV, 15 mM K+ -treatment with different voltage-gated ion channel antagonists. Scale bar, 20 μm; dotted line, soma. b, Mean ankyrin G positions (TTX, 392 cells, 16 coverslips; Ni2+, 193 cells, 8 coverslips; SNX, 247 cells, 10 coverslips; mibefradil, 246 cells, 10 coverslips; ω-agatoxin-TK, 199 cells, 8 coverslips; ω-conotoxin-GVIA, 199 cells, 8 coverslips; nifedipine, 200 cells, 8 coverslips). *, P < 0.05; ***, P < 0.001; error bars, s.e.m.