Fig. 2. Stimulation by GO/rGO coatings elicits distinct EXT-Ca²⁺ and INT-Ca²⁺ dynamics.

a,b, Representative traces of Ca²⁺ imaging observed after positive voltage bias stimulation of astrocytes, starting at time t ≈ 25 s from the beginning of the experiment (insets to panels 1) plated on GO–ITO- (a) and on rGO–ITO-coated electrodes (b). Different panels refer to the different conditions of the cells exposed to standard bath solution (CTRL, 1) and solution without extracellular Ca²⁺ (NO EXT-Ca²⁺, 2) and in the presence of VGCC inhibitor verapamil (VERAP, 25 μM, 3), TRPV4 inhibitor RN-1734 (RN, 10 μM, 4), TRPA1 inhibitor HC-030031 (HC, 40 μM, 5), IP₃ receptor pathway inhibitor 2-aminoethoxy diphenyl borate (2-APB, 100 μM, 6), SERCA inhibitor cyclopiazonic acid (CPA, 10 μM, 7), RyR activator caffeine (CAFF, 20 mM, 8), RyR inhibitor ryanodine (RYAN, 50 μM, 9), G_q–PLC inhibitor U73122 (0.5 μM, 10) and G_i/o inhibitor pertussis toxin (PTX, 500 ng ml⁻¹, 11).