Saikosaponin a Enhances Transient Inactivating Potassium Current in Rat Hippocampal CA1 Neurons

Figure 5

Effects of SSa on the steady-state inactivation properties of 𝐼_𝐴. (a) Typical traces of 𝐼_𝐴, under control condition (top panel) and after application of 1 μM SSa (middle panel). Currents were elicited with a series of 120 ms prepulses at different hyperpolarizing potentials between −90 mV and +10 mV in 10 mV increments, followed by an 80 ms depolarizing pulse to +50 mV, delivered every 10 s (bottom panel). Currents at the end of the depolarizing pulse represented 𝐼_𝐴. (b) The steady-state inactivation curves for 𝐼_𝐴 in the absence and presence of 1 μM SSa. The peak amplitudes of 𝐼_𝐴 were normalized and plotted against the prepulse potentials and the data were fitted with the Boltzmann function. Data are represented as mean ± SEM (𝑛=8). ^∗𝑃<0.05 (versus control).

(a)

(b)