Figure 4.
[Ca2+]i increase and decay at bouton, bottleneck, and axonal regions along mf4–Ib terminals. For both single APs and 20 Hz stimulation, the increase in [Ca2+]i was significantly greater at boutons than at axons, but there was no significant difference between boutons and bottlenecks. The [Ca2+]i decay τ was significantly greater at axons than boutons for both single APs and AP trains, but there was no significant difference between boutons and bottlenecks. The data are from four terminals, providing measurements from 67 boutons, 14 bottlenecks, and 4 axons. *p < 0.01; **p < 0.001, significantly different from bouton.