Early glycinergic axon contact with the Mauthner neuron during zebrafish development

► Anti-glycine antibody was used for the first time in zebrafish. ► The glycinergic axons contact to the Mauthner neuron first by 27 h post fertilization. ► The stochastic genetic labeling with GlyT2:GFP was performed. ► The origin of these axons was identified as spinal commissural neurons.