CNAα and CDK5 regulate 1AP-stimulated vesicle release at nerve terminals. A, Ensemble average traces of 1AP-stimulated exocytosis reported by vG–pH in WT, CNAαKD, and CDK5KD synapses. B, Mean values of 1AP vG–pH response amplitudes normalized to WT in WT, CNAαKD, CDK5KD, and WT neurons treated with roscovitine (Ros). WT_1AP = 1.00 ± 0.12 (n = 20), CNAαKD_1AP = 0.23 ± 0.08 (n = 8), CDK5KD_1AP = 1.61 ± 0.13 (n = 8), and WT + Ros_1AP = 1.65 ± 0.25 (n = 10). C, Ensemble average of 1AP-stimulated exocytosis recorded by vG–pH in WT and WT with Ros and CSA simultaneously. D, Mean values of 1AP responses of vG–pH in WT and WT with Ros and CSA simultaneously. WT_1AP = 1.00 ± 0.12, and WT + Ros + CSA_1AP = 1.05 ± 0.09 (n = 9). E, Ensemble average of 1AP-stimulated exocytosis recorded by vG–pH in CNAαKD and CNAαKD with Ros. F, Mean values of 1AP vG–pH responses in CNAαKD and CNAαKD treated with Ros. CNAαKD_1AP = 0.17 ± 0.06, and CNAαKD + CSA_1AP = 0.19 ± 0.06 (n = 8). G, Mean amplitudes of 1AP vG–pH response in WT neurons normalized to control WT condition for ω-agatoxin IVA (Aga) or ω-conotoxin GVIA (Cono) treatments: WT_1AP = 1 ± 0.18 (n = 17), WT + Aga_1AP = 0.52 ± 0.13 (n = 7), and WT + Cono_1AP = 0.28 ± 0.04 (n = 10). H, Mean amplitudes of 1AP vG–pH responses in CNAαKD neurons normalized to control WT conditions for ω-agatoxin IVA and ω-conotoxin GVIA treatments: CNAαKDonly_1AP = 0.17 ± 0.09 (n = 16), CNAαKD + Aga_1AP = 0.06 ± 0.06 (n = 10), and CNAαKD + Cono_1AP = 0.16 ± 0.04 (n = 6). I, Mean amplitudes of 1AP vG–pH response in WT neurons normalized to WT control condition for Aga and Aga + Ros treatments: WT_1AP = 1 ± 0.24 (n = 5), WT + Aga_1AP = 0.50 ± 0.12 (n = 5), and WT + Aga + Ros_1AP = 1.17 ± 0.15 (n = 5). J, Mean amplitudes of 1AP vG–pH response in WT neurons normalized to WT control condition for Cono and ω-Cono + Ros treatments: WT_1AP = 1 ± 0.13 (n = 9), WT + Cono_1AP = 0.30 ± 0.1 (n = 9), and WT + Cono + Ros_1AP = 0.35 ± 0.07 (n = 9). *p < 0.05, **p < 0.01. NS, Not significantly different.