Fig. 4

BzATP increases [Ca²⁺]_i by gating P2X7Rs. Microglia grown on coverslips were incubated with 5 μM Fluo-4-AM for 30 min, followed by 30 min in dye-free medium to allow de-esterification. 300 μM BzATP application (black trace) stimulated an immediate rise in fluorescence that plateaued during constant agonist exposure. No change in [Ca²⁺]_i was measured in the absence of extracellular Ca²⁺ (blue trace). BzATP-induced increase in [Ca²⁺]_i fluorescence was unaffected by addition of the non-selective Ca²⁺ channel blocker, cadmium (200 μM) (red trace). Inset shows quantification of fluorescence changes over time, measured as the fold change in fluorescence over baseline after background subtraction (F/F₀) for 7–11 separate experiments for each paradigm. Significance was determined using ANOVA