Fig. 1
Extracellular ATP evokes Ca2+ entry in highly pure primary cultures of human microglia. a, b Representative immunofluorescence images of primary cultures of human microglial cells (patient #12) marked with Iba1 and GFAP antibody (red and green, respectively) and nuclei marked with Hoechst 33258 (blue). Horizontal bar = 20 μm. Please note in b the presence of a single astrocyte. c Typical time-course of [Ca2+]i changes elicited by ATP application (100 μM, 1 min, horizontal line) in a single human microglial cell (#9). d Typical time-course of [Ca2+]i changes elicited by ATP application in the absence of external Ca2+ (10 min preincubation; #10). e Typical time-course of [Ca2+]i changes elicited by ATP application in a human microglial cell pretreated with LPS for 48 h (#12). f Histogram representing the percentage of microglial cells responding to ATP in control conditions (62 out 62 cells, 16 optical fields, #9), in Ca2+-free medium (15 out 23 cells, 4 optical fields, #10; one asterisk denotes significantly different from control, p=0.023) or after LPS treatment (41 out 42 cells, 6 optical fields, #12). g Histogram representing the mean amplitude of ATP-induced Ca2+ elevations, same cells as c, d, and e. Two asterisks denote significantly different from both other values, p<0.001. Black circles represent individual values