mnbf01371 mutant NMJs have fewer synaptic boutons compared to controls, but the remaining boutons are larger in size.
mnbf01371 mutant larvae exhibit synaptic vesicle endocytosis defects: the level of membrane uptake (dye internalisation) in mutant synaptic boutons in response to nerve stimulation is significantly reduced compared to controls. When dye unloading occurs in response to a second stimulation, the mnbf01371 mutants unload a similar amount of dye to controls, suggesting exocytosis is unaffected.