Figure 6.

SST₄ mediates SST increase in M-current. A, Representative current traces from CA1 hippocampal neurons of wild-type, SST₂ and SST₄ knock-out mice evoked by stepping from a holding voltage of −40 to −60 mV for 1 s. Note the increase in outward holding current (double arrows) and the inward “relaxation” (single arrows) in the presence of 1 μm SST (gray traces) in wild type and SST₂ knock-outs, but not SST₄ knock-outs. B, Summary of current-voltage data for SST-induced current in CA1 neurons from wild-type and SST₂ and SST₄ knock-out mice. Neurons were held at approximately −40 mV and 5–10 mV hyperpolarizing voltage steps given. Currents in presence of 1 μm SST were subtracted from control currents to obtain the net SST-induced current. Net SST current is similar in wild type and SST₂ knock-outs, whereas in SST₄ knock-outs SST-induced current is mostly absent. Error bars indicate SEM. Asterisk indicates significant difference from wild type.