Supplementary Figure 1: FFN200 accumulates in cultured dopamine neurons.

(a) Representative images of FFN200-labeled dopamine ventral midbrain neurons obtained from TH-GFP mice, displaying different levels of FFN200 accumulation following incubation with 10 μM FFN200 for 30 min at 37°C. (b) Scatter plot of FFN200 intensity values at GFP-positive dopamine neurons, presented in ascending order in a logarithmic scale. Neurons were considered FFN200-positive when their fluorescence intensity was greater than two standard deviations above the mean FFN200 intensity of GFP-negative cells (the threshold is depicted as a dotted line; 80 cells from six dishes, four independent cultures). An example of an FFN200-negative neuron is shown in the top TH-GFP/FFN200 image pair in panel (a), and the following two image pairs show FFN200-positive neurons.