Figure 5.

Amplitude of fast-activating BK current correlates with burstiness. A, BK currents recorded in response to voltage steps, averaged over four steps from a holding V = −40 to 0, 10, 20, and 30 mV. The voltage steps were performed before and after pharmacological BK block, and the difference current was computed. The two traces correspond to two different cells, one bursting in control conditions (*), one spiking (+). B, Scatter plot of the burstiness in control conditions and the BK current measured (in the same cells) as illustrated in A and averaged over the periods of time shown (early, late). Burstiness and amplitude of the early component of the BK current are positively correlated (left, r = 0.74, p < 0.01). In some cells, a slow component of BK current is observed that contributes significantly to the late part of the current. The amplitude of the late part of the current is not correlated with burstiness (right). The * and + signs correspond to the cells whose currents are shown in A.