α-DTX blocks IKlt and the slow rate increase. A, PSTH (top), voltage response or command (middle), and current injection or response (bottom) of an NM neuron in hybrid clamp in normal ACSF. The dotted line represents the recording mode versus time (VC, voltage clamp; IC, current clamp). The arrow indicates the large, slowly inactivating outward current during the depolarizing voltage-clamp step. B, PSTH, voltage, and current (as in A) of the same neuron in the presence of 100 nm α-DTX. The arrow shows the reduced outward current during the depolarizing voltage-clamp step. C, Mean change in firing rate versus conditioning voltage for NM neurons in control ACSF (n = 14; open triangles) and 100 nm α-DTX (n = 7; filled diamonds; *p < 0.01, Bonferroni's corrected t test). Error bars represent SE.
