Rtnl1 loss decreases miniature neurotransmission frequency. (Extended data from Fig. S7, D–E.) Representative examples (close to the median frequency) of miniature events in 100 frames over 8 s (12.5 frames/s). Panels show time-lapse GCaMP fluorescence at rest in distal boutons of muscle 1, Type Is postsynaptic terminals, in WT (two boutons) and Rtnl1¹⁸ (four boutons). Arrows indicate miniature events counted. Genotypes are Is-GAL4, mhc-SynapGCaMP6f/UAS-tdTom::Sec61β, in either a WT or Rtnl1¹⁸ background.