FIGURE 6.

Anti-NR1 siRNA attenuates mitochondrial uptake of Ca²⁺. GT1-7 cells were transfected with siRNA against NR1 for 72 h, which resulted in reduced NR1 protein expression (A), which is quantified in optical density units (B). *, p < 0.001. C, mitochondria isolated from cells transfected with siRNA or scrambled RNA that were exposed to calcium had base-line (control) [Ca²⁺]_m levels. As demonstrated in Fig. 2, mitochondria prepared from control cells and exposed to both calcium and NMDA showed a 2-fold increase in [Ca²⁺]_m. In contrast, cells in which NR1 was knocked down failed to take up Ca²⁺ following the addition of NMDA and calcium, whereas scrambled RNA-transfected cells, like control cells, showed an ∼2-fold increase in [Ca²⁺]_m under similar conditions. *, p < 0.001 versus the control.