Figure 4.

DISC1 loss-of-function reduces evoked Ca²⁺ transients at nerve terminals. SyGC3 imaging in rat hippocampal neurons (DIV14–16) in response two different trains of APs. (A) Average Ca²⁺ transients in neurons expressing scr (1052 boutons, 15 fields, 5 experiments (exps)), DISC1-E (1836 boutons, 9 fields, 3 exps) and -A (754 boutons, 11 fields, 3 exps) shRNAs, in response to 300 APs, 10 Hz. The DISC1-E and DISC-A groups are significantly different than the scr group (p = 0.0057). (B) Average Ca²⁺ transients in neurons expressing scr (861 boutons, 9 fields, 5 exps), DISC1-E (2118 boutons, 7 fields, 3 exps) and -A (1549 boutons, 9 fields, 3 exps) shRNAs, in response to 200 APs, 20 Hz. (C) Cumulative probability of SyGC3 peak intensity from individual boutons corresponding to (A). (D) Average Ca²⁺ transients in DISC1^wt/wt (1090 boutons, 11 fields, 3 exps) and DISC1^{Δ2–3/Δ2–3} (727 boutons, 9 fields, 3 exps) neurons, in response to 300 APs, 10 Hz. The DISC1^wt/wt and DISC1^{Δ2–3/Δ2–3} groups are statistically different (p = 0.0182). (E) Average Ca²⁺ transients in DISC1^wt/wt (1365 boutons, 9 fields, 3 exps) and DISC1^{Δ2–3/Δ2–3} (1233 boutons, 8 fields, 3 exps) neurons, in response to 200 APs, 20 Hz. (F) Cumulative probability of SyGC3 peak intensity from individual boutons corresponding to (D). (G) Average Ca²⁺ transients in neurons expressing scr (290 boutons, 6 fields, 2 exps), and DISC1-E (390 boutons, 6 fields, 2 exps) shRNAs, in response to 20 APs, 20 Hz. The scr and DISC1-E groups are statistically different (p = 0.0036). (H) Average vGpH traces in scr (180 boutons, 5 fields, 2 exps) and DISC1-E (488 boutons, 6 fields, 2 exps) shRNA-expressing neurons during two consecutive trains of APs (300 AP, 10 Hz) in the presence of 2 or 4 mM extracellular Ca²⁺.