Fig. 3.

Functional synaptic vesicle pools in synuclein-deficient synapses. Synapses in cultured cortical neurons were loaded with FM1-43, and the size of the pool of actively recycling vesicles was determined as the amount of FM1-43 fluorescence that could be released upon repeated depolarization (3 × 90 mM K⁺ for 90 s) in the absence of exogenous FM1-43. Shown is the frequency distribution of FM1-43 labeling of synaptic boutons in cultures from α-synuclein (Top), β-synuclein (Middle), and α/β-synuclein double-KO (Bottom) neurons (in each case, compared with the corresponding distribution obtained with littermate control mice).