Fig. 8: Synapsin 2a’s nanoscale organization is regulated by synaptic activity and this effect is tetramerisation-dependent.

a, c Average mean square displacement (MSD; µm²) of mEos3.1-tagged (a) wild-type (WT) Synapsin 2a (Syn2a^WT-mEos3.1; cyan) and (c) tetramerization deficient Synapsin 2a K337Q (Syn2a^K337Q-mEos3.1) (magenta) within the presynapses before (resting) and after stimulation. b, d Area under the MSD curve (AUC; µm² s) of (b) Syn2a^WT-mEos3.1 (cyan) and (d) Syn2a^K337Q-mEos3.1 (magenta) within the presynapse, before (resting) and after stimulation. e, f The effect of stimulation on the number of Syn2a^WT-mEos3.1 trajectories detected in the (e) axonal and (f) presynaptic compartment of Synapsin triple knockout (SynTKO) hippocampal neurons normalized by the area (traj/µm²). g, h The effect of stimulation on the number of Syn2a^K337Q-mEos3.1 trajectories detected in the (g) axonal and (h) presynaptic compartments of SynTKO hippocampal neurons normalized by the area (traj/µm²). Data are displayed as mean ± SEM. Values were obtained from n  =  18 presynapses (Resting) and n = 11 presynapses (After Stimulation) in (a–d); from n  =  37 axons (Resting) and n = 8 axons (After Stimulation) in (e); from n  =  39 presynapses (Resting) and n = 10 presynapses (After Stimulation) in (f); from n  =  44 axons (Resting) and n = 7 axons (After Stimulation) in (g) and from n  =  37 presynapses (Resting) and n = 9 presynapses (After Stimulation) in (h). Data were obtained from two biological replicates. Statistical comparisons were performed using the unpaired two-tailed Student’s t test in (b, d, e, h) and the unpaired two-tailed Mann–Whitney U test in (f) and (g). Source data are provided as a Source Data file.