Figure 6. The GABA_B receptor‐sensitive outward current is linked to calcium channels and BK channels .

A, an outward current was elicited by a step from −70 to +10 mV (black trace). This was repeated in the presence of 100 μm cadmium (red trace), which blocks voltage‐gated calcium channels. Further addition of 10 μm baclofen had no additional effect (green trace). This indicates that baclofen suppresses a calcium‐dependent potassium current. B, a step from −70 to +10 mV produced an outward current (black trace) that was reduced by 1 mm TEA, a selective BK channel blocker (red trace). In the presence of TEA, baclofen did not further reduce the outward current (blue trace). C, data summarizing the effects of TEA (n = 9) or cadmium (n = 9) with, or without, baclofen. Baclofen reduced the outward current by 21 ± 1% (P < 0.01 compared to control), TEA alone reduced the outward current by 33 ± 3% (P < 0.01 compared to control), while TEA plus baclofen reduced the outward current by 35 ± 4% (P < 0.01 compared to control). Cadmium reduced the outward current by 22 ± 4%, while the addition of baclofen in the presence of cadmium produced no additional effect on outward current.