Inhibition of SK improves cholinergic excitability in TgCRND8 mice. A, Representative example of cell firing elicited by bath application of 1 mm ACh (15 s) in WT (top, blue trace), TgCRND8 (middle, red trace), and a TgCRND8 cell in the presence apamin (bottom, black trace). Traces represent the first 15 s of ACh-elicited firing. B, Apamin induces a rightward shift of the cumulative probability distribution of ACh-elicited firing frequency in TgCRND8 (K–S test, p < 0.00001; TgCRND8 control, n = 15 cells, TgCRND8 + Apamin, n = 8 cells).