Fig 5. Pharmacological inhibitors of IP₃ receptors abrogate high [K⁺]_e-induced Ca²⁺ transients in Ca²⁺-free bath solution.

A: Representative time courses of changes in cytosolic ΔF/F₀ in response to two consecutive 30-s exposures to 80 mM [K⁺]_e in 2 mM [Ca²⁺]_e (left panels) and in Ca²⁺-free bath solution (with 200 μM EGTA added; right panels) following 20-min incubation with 20 μM 2-APB or 10 μM xestospongin C. B: Percentage of neurons exhibiting [Ca²⁺]_i transients both in 2 mM and 0 mM [Ca²⁺]_e; * P < 0.001 versus control by Fisher’s Exact test (60, 6 and 16 cells for control, 2-APB and xestospongin C, respectively).