Panel A and B show fluorescent images of astrocytes treated with DMSO, 2-APB, and BAPTA-AM, highlighting the accumulation of LAMP1 and Rab5a organelles in the perinuclear region over time. Arrowheads indicate clustered organelles. Panel C and D present kymographs illustrating the effects of BAPTA-AM and photobleaching on LAMP1-mCherry and Rab5a. Panel E and F display images of process elongation in astrocytes after local illumination, with measurements taken at baseline, 30 minutes, and 60 minutes. Panel G is a line graph comparing process elongation between untreated and illuminated groups over time, with statistical analysis indicating significance levels.
Ca 2+ signaling facilitates organelle entry into astrocyte process termini. (A and B) Organelles progressively accumulate in the perinuclear region, as evidence by the increased signal intensity following 2-APB (100 µM) or BAPTA-AM (100 µM) treatment. Arrowheads: clustered organelles. Scale bars: 10 μm. Related to Videos 14 and 15. (C and D) Effects of BAPTA-AM (100 µM, 1 hr) and photobleaching (magenta box) on LAMP1-mCherry (C) and Rab5a (D). Kymographs were generated from the bleached process segments over 500 frames at 5-s intervals. Scale bars: 5 μm. Related to Videos 16 and 17. (E and F) Process elongation after three rounds of 4-s Local illumination at 30-min intervals. Untreated cells as controls. Process length was quantified at three time points: baseline, 30 min, and 60 min after the first illumination for both control and 4-s illumination groups. Scale bars: 5 μm. (G) Comparison of process elongation between the untreated group (Control) and 4-s illumination group (Local) up to 60 min. Related to E and F. Data analysis was performed using a two-tailed unpaired t test after normality verification by the Shapiro–Wilk test, ns, not significant; **P < 0.01. n = 6 independent experiments.