Figure S1.

Human review of auto-detected presynapses in the FAFB-FlyWire dataset, related to Figures 3 and 2

(A) Empirical cumulative density distribution curve for review of 4,306 automatically detected preynapses from the FAFB-FlyWire dataset. A presynapse comprises the synaptic machinery and vesicles on the source neuron’s side of the synaptic cleft. Detected preynapses have a “cleft score” that ranges between 0 to over 200, which indicates how discriminable the synaptic cleft at the presynaptic site is for the detection network.¹² Our threshold of 50 is indicated by a vertical grey line. Green, determined to be a true presynapse by a human annotator; pink, determined to not be a true presynapse.

(B) Rates of false presynapse detection across cleft scores, transmitter types, and compartments. We sampled ∼180 for each set of conditions. We sampled ∼10 presynapses per cleft score bin (width 10), presynaptic transmitter prediction type (columns) and neuronal compartment (rows). Histograms show the number of presynapses determined to be real (green) or not (red) by a human annotator (A.S.B). Presynapses were reviewed using the flywire interface.¹⁷