Figure 3. Blockade of the Na-Ca exchanger (NCX) increases [Ca²⁺]_i and reduces vulnerability to MG-132-induced neuronal death.

Left panel: [Ca²⁺]_i measurements. Murine neocortical cultures were sham-washed (SHAM) or treated with benzamil (BENZ, 10 μM) for 4 hr in the absence (left two SHAM bars) or presence of MG-132 (MG, 1 μM) and then [Ca²⁺]_i was measured as in Figure 1A. * indicates values were significantly different (P<0.05 by ANOVA with Bonferroni post hoc) from those in sham-washed condition without benzamil (left most bar). # indicates that cultures with BENZ+MG-132 differed from those treated with MG-132 alone. Values for MG-132 cultures treated with BENZ did not differ significantly from those in sham-washed condition without BENZ. Right panel: Cultures were treated with MG-132 (MG, 0.3 or 1.0 μM) for 48 hr in the presence or absence of benzamil (BENZ, 10 μM). Values shown are mean ± SEM cell death as assayed by propidium iodide fluorescence at the end of the 48 hr treatment period. * indicates values in +BENZ condition differ significantly from treated with MG alone.