Dendrotoxin transforms accommodating and silent principal cells into neurons capable of firing trains of spikes. Shown are current-clamp recordings of an accommodating principal cell before (A) and after (B) 200 nm DTX exposure in normal ACSF. C, A plot of the number of spikes in 300 msec versus injected current amplitude for accommodating principal cells (•, n = 5), firing principal cells (○, n = 5), accommodating principal cells after exposure to DTX (▵, n = 5), and silent principal cells (◊, n=3) after exposure to DTX.