Fig. 1.

Comparison between [Ca²⁺]_i responses elicited by weak and strong depolarization and their sensitivity to FCCP in fura-2 AM-loaded sympathetic neurons. a, [Ca²⁺]_i responses from a sympathetic neuron in primary culture elicited by weak depolarization (30 mm K⁺) before (left) and after (right) treatment with 1 μm FCCP.b, [Ca²⁺]_i responses elicited from the same cell by stronger depolarization (50 mm K⁺) before (left) and after (right) treatment with 1 μm FCCP. In this cell, the initial rate of recovery after repolarization was −71 nm/sec in the absence of FCCP, whereas the rate of decline in the presence of FCCP measured over the same range of [Ca²⁺]_i was −18 nm/sec. Collected results indicate that FCCP slows the rate of recovery to ∼14% of the control value (from −121 ± 15 nm/sec to −17 ± 3 nm/sec; n = 11) measured over the same range of [Ca²⁺]_i. Cell b13j.c, [Ca²⁺]_i response recorded from a cell (b16f) on the periphery of a ganglion like those used in this study for EDX microanalysis. This ganglion was treated enzymatically according to the same procedure used to prepare dissociated cells, but cells were not dispersed by trituration.