Fig. 4.
The frequency of VAMP3 exocytosis in primary rat oligodendrocytes is much lower than that of human melanoma cells. (A) Representative image of segmented oligodendrocyte (OL) and event detail. Scale bar: 10 µm. (B) Quantification of exocytosis with manual (0.0038±0.0005) and automated (0.0041±0.0006) detection (mean±s.e.m., n=21 cells). Frequencies reported as number of events/µm2/min. Cells expressing both VAMP3–sepHluorin and tetanus toxin light chain (TeNT) were quantified manually (0.00012±3.6×10−5) and automated (0.0002±5.6×10−5). (C) Representative image of 1205Lu human melanoma cell line and example exocytic trace. Scale bar: 10 µm. (D) Frequency of VAMP3–sepHluorin exocytosis in primary rat OL (0.0041±0.0006) and 1205Lu cells (0.12±0.011, mean±s.e.m., n=21). (E) Frequency of exocytosis in 1205Lu cells imaged at 2 Hz (0.067±0.0077, mean±s.e.m., n=23) and 4 Hz (0.12±0.011, mean±s.e.m., n=21). For box plots, the box represents the 25–75th percentiles, and the median is indicated. The whiskers show the smallest and largest non-outlier values (within 1.5×IQR from the Q1 and Q3 boundaries).