Figure 2. Ca²⁺ dependence of mitochondrial Ca²⁺ uptake in permeabilized sympathetic neurons.

Sympathetic neurons infected with mitmutAEQ and reconstituted with coelenterazine n were permeabilized by treatment with 20 μm digitonin over 1 min at 37°C in Ca²⁺-free (containing 0.2 mm EGTA) intracellular-like medium (composition, in mm: NaCl, 5; KCl, 130; MgCl₂, 2; KH₂PO₄, 2; Mg-ATP, 0.2; and potassium-Hepes, 20; pH 7.0 adjusted with KOH). Then the cells were perfused with ‘intracellular-like’ medium containing different [Ca²⁺] values, as shown in the figure. The different [Ca²⁺] values were obtained using buffers containing 1 mm EGTA or 1 mm N-(hydroxyethyl) ethylenediamine triacetic acid (HEDTA) and adjusting Ca²⁺ and Mg²⁺ as required (Patton et al. 2004). Values represent the mean ± s.e.m. of 5 different cells present in the same microscopic field. Results are representative of 5 similar experiments.