IFN-γ increases the proportion of directional dextran labeled vesicles in live WT mouse astrocytes. Graph shows MD as a function of total TL over 30 s. Vesicles with MD >1 μm (dashed line) were characterized as directional vesicles (black circles; nd, number of directional vesicles). Other vesicles were characterized as non-directional vesicles (white circles; nn, number of nondirectional vesicles). (a) The percentage of directional vesicles in IFN-γ-treated WT cells was greater than in untreated control cells (20.3% vs. 8%; P <0.001). After ATP treatment, the percentage of directional vesicles decreased from 8% to 5.2% (P <0.01) in control cells and from 20.3% to 5.9% in IFN-γ-treated WT cells (P <0.001). (b) The percentage of directional vesicles in IFN-γ-treated GFAP
-/- astrocytes did not change significantly compared to untreated control cells (4.4% vs. 5.7%, P = 0.081). After ATP treatment, the percentage of directional vesicles was not affected in control cells (4.4% vs. 3.9%; P = 0.602), but was reduced from 5.7% to 2.5% in IFN-γ-treated GFAP
-/- cells (P <0.001). Note that the slopes of the lines fitted for directional and non-directional vesicles are presented in Table 2.