Figure 6. The 2‐PAA‐induced increase in gap junction coupling was Ca²⁺ dependent.

A, application of 2‐PAA (20 μm) increased the intracellular Ca²⁺ signal (fluorescence ratio F ₃₄₀/F ₃₈₀). The columns show the results obtained by counting the amount of cells with an increased [Ca²⁺]_i after treatment with the vehicle control (cont., 0.3% ethanol) or 2‐PAA (20 μm) in presence of 140 mm external Na⁺. B, a representative rapid transient Ca²⁺ signal induced by application of 2‐PAA (20 μm) when external Na⁺ was replaced by NMDG. C, the 2‐PAA‐induced increase in the dye diffusion distance was abolished when 2‐PAA (20 μm, 1 h) was applied on cells preloaded with the Ca²⁺ chelator BAPTA (10 μm) or in absence of external Ca²⁺ (‐ Ca²⁺ _extracell.). All results were analysed using Student's t test. ^*Significant differences to the vehicle control: ^* P < 0.05: ^*** P < 0.001; ^#significant differences to 2‐PAA: ^## P < 0.01.