Figure 6.

Activation of hSNSR4 inhibits M-type K⁺ channels in rat SCG neurons. A, B, Comparison of BAM8-22 (BAM)-induced inhibition of M-type K⁺ current (I_M) in control (Con) and hSNSR4-expressing neurons. Representative I_M traces (top) recorded from an uninjected (A) and hSNSR4-expressing (B) SCG neurons in the absence (control) or presence of BAM8-22 (3 μm). I_M was evoked from a holding potential of -30 mV with the voltage protocol illustrated (A). The dashed line represents the zero current level. Time courses of I_M amplitude (below) from the same neurons in the absence or presence of BAM8-22. I_M amplitude was determined as the current component deactivating during a 500 msec voltage step to -60 mV (arrows in A, top). C, hSNSR4-mediated inhibition of I_M was insensitive to overnight pretreatment with PTX (0.5 μg/ml). Mean (±SEM) percentage I_M inhibition was produced by application of BAM8-22 under the conditions indicated. I_M inhibition was determined from traces acquired just before and 1 min after the start of agonist application. The number of neurons tested is indicated in parentheses. Uninj., Uninjected.