Munc13-1 and CaV2.1 nanoclustering. a–c, Example STED images of sideview synapses (a), quantification of line profiles (b) and Pearson’s colocalization coefficients (c). Cultured hippocampal neurons stained with antibodies against Synapsin and Munc13-1, and a second Munc13-1 antibody or a CaV2.1 antibody. Side-view synapses were identified by the presence of an elongated Munc13-1…