Figure 9.

Analysis of Ican induction after a spike train in AOB mitral cells. A, The hybrid-clamp protocol. A burst of spikes was elicited in current-clamp mode by a depolarizing current pulse train (duration, 4 s; rate, 20 Hz; amplitude, 300 pA; width, 10 ms), followed by a switch to voltage-clamp mode. The hybrid-clamp modes are indicated in the bar above. The dashed line gives the baseline current. The stimulus train induced a transient outward current followed by a slow prolonged inward current of ∼10 pA. B, The protocol for measuring the reversal potential of the prolonged current. Several voltage ramps were given before and after the spike train (marked by a green bar). C, I–V curves before and after the pulse train, using the ramps color coded in B. The conductance was calculated from the change in slope between the curves, and the reversal potential was calculated from the intersection of their extrapolated linear fits. D, The averaged current after the pulse train (green bar) to AOB mitral cells in the control condition (dotted line, 9 cells) and in slices incubated with blockers of N- and R-type VACCs (continuous line, 9 cells). E, The inverse of the charge transferred in the prolonged current from 2 to 34 s after spike train (left) in control conditions (green, 8 cells) and after intracellular calcium stores depletion by thapsigargin (magenta, 3 cells) or after a DHPG puff (right) in the same conditions (control, 10 cells; thapsigargin, 6 cells). Bars and error bars represent mean ± SEM; Mann–Whitney U test, *p < 0.05.