Fig 5. SVs disperse upon forskolin-induced presynaptic potentiation in cryo-fixed acute slices.

(A) Partial 3D reconstruction of hippocampal mossy fiber boutons in control conditions or after forskolin treatment. Presynaptic membrane is green, postsynaptic membrane is light blue, and SVs are blue (control) or red (forskolin). (B) Bar graphs indicating the quantification of SV density per cubic micron of reconstructed volume; SV density was comparable in forskolin-treated and control terminals (p = 0.5639, unpaired t test). (C) Bar graphs indicating the quantification of SV distance from other SVs normalized by the volume of the reconstruction (nm/μm³); distance between vesicles was increased in forskolin-treated terminals (p = 0.0050, Mann–Whitney U test). (D) Bar graphs indicating the quantification of MNND between vesicles (nm); MNND was comparable in forskolin-treated and control terminals (p = 0.1946, Mann–Whitney U test). In all graphs, scatter points indicate individual boutons, n = 22 boutons for control and 20 boutons for forskolin-treated slices from 4 animals. Values represent mean ± SEM. CTRL, control; FSK, forskolin; MNND, mean nearest neighbor distance; MW, Mann–Whitney U test; SV, synaptic vesicle; ut-t, unpaired t test. The data underlying this figure can be found at doi: 10.5281/zenodo.4498214.