Figure 4.

Noradrenaline-mediated Ca²⁺ response is reduced in astrocytes expressing RFP-TDP-43^208–414 compared with RFP-TDP-43^wt-expressing astrocytes. (A) Representative fluorescence images of RFP-TDP-43^wt-expressing astrocytes labeled with Ca²⁺ indicator Fluo-4 AM and stimulated with noradrenaline (NA, black line). Scale bar: 20 µm. (B) Mean intensity changes in intracellular Ca²⁺ (ΔF/F₀) upon stimulation with 100 µM NA (black line) in astrocytes expressing RFP-TDP-43^wt (n = 55; black circles) and RFP-TDP-43^208–414 (n = 162; gray circles). Each data point represents the mean ± SEM. (C,D) Mean peak amplitude (C) and cumulative Ca²⁺ response (D; ΔF/F₀) upon the addition of NA for RFP-TDP-43^wt and RFP-TDP-43^208–414 experimental groups. Numbers adjacent to the error bars depict the number of cells analysed. Data are presented as means ± SEM and acquired from four different animals (multiple cells were recorded per coverslip). Asterisk denotes statistical significance, *P < 0.05, determined by the Mann-Whitney U test.