Analysis of the differential Ca2+ storage and regulation of the ER and mitochondria by pharmacological intervention in WT and G93A transfected SH-SY5Y cells. Cells were stimulated using thapsi and FCCP, which interfere with the integrity of the ER and mitochondria, respectively, and were used to release Ca2+ from intracellular stores by inhibition of the sarcoplasmic/endoplasmic reticulm Ca2+-dependent ATPase pump and mitochondrial stores by protonophore action. A) The quantitative kinetic profile of the thapsi and FCCP-evoked [Ca2+]i release in WT transfected SH-SY5Y cells. B) The corresponding quantitative kinetic profile of the thapsi and FCCP-evoked [Ca2+]i release in the G93A transfected SH-SY5Y cells. The trace is representative of mean of 4–6 cells in focus stimulated with thapsi (5 μg/ml; 6 min) and 2 μM FCCP (3 min, normalized data). The horizontal black bars indicate the duration of stimulation by thapsi and with FCCP plus thapsi. Fura-2 AM signals are represented as F/F0. C) A bar diagram of thapsi and FCCP plus thapsi-induced Ca2+ release in the WT and G93A transfected SH-SY5Y neuroblastoma cells (N = 3, n = 15). Gray bars represent thapsi plus FCCP-induced Ca2+ release in WT (F/F0 = 0.2712 ± 0.0971) and G93A (F/F0 = 0.1276 ± 0.0287) transfected SH-SY5Y cells. Striped bars represent thapsi-induced Ca2+ release in WT (F/F0 = 0.0412 ± 0.0152) and G93A (F/F0 = 0.0258 ± 0.0137) transfected cells. Values represent means ± SD, *p < 0.01, **p < 0.001. N = Number of experiments; n = Number of cells.