Figure 5.
Effect of mitochondrial inhibitors on [Ca2+]i and Δψm in striatal neurons. Experiments were performed in WT and YAC128 neurons, loaded with fluo5-F and equilibrated with TMRM+, in media with 10 mm pyruvate in the absence of glucose and Mg2+. A, Changes in [Ca2+]i (a), Δψm (b), and somatic area (c) induced by oligomycin (2 μg/ml) followed by ionomycin (2 μm). Representative tracings are from YAC128 neurons (similar tracings are observed in WT neurons although in different proportions as deducible from B). Tracings from i to iv represent distinct neurons with increasing degrees of susceptibility to oligomycin as observed by the progressively earlier onset of Ca2+ elevation. B, Quantitative analysis of the increasing number of neurons with elevated [Ca2+]i after ATP synthase inhibition (oligomycin). YAC128 (black circles) elevate [Ca2+]i within a shorter time than WT (white circles) neurons (black vs white bar, *p < 0.05, n = 3, comprising 300 neurons per genotype). Values are mean and SEM. C, Representative single neuron recordings illustrating the continuous elevation of Ca2+ (no [Ca2+]i plateau) when mitochondria are depolarized with oligomycin and rotenone (1 μm). See Results for a detailed description of the individual tracings.