Fig. 4.

Calcium-loading capacity of brain mitochondria. Assessment of calcium loading capacity was performed on isolated brain mitochondria from thirteen-lined ground squirrels. Briefly, CaCl₂ (260 μM) was titrated into the chamber upon the addition of succinate (10 mM) to stimulate approximately state 4 respiration (see materials and methods for details). The estimation of calcium-loading capacity was determined after calcium loading halted in the mitochondrial suspension. SP, n = 6; TOR, n = 7; IBA, n = 6. **P < 0.01, Tukey’s HSD.