NO donor prevents PDI-mediated protection of primary neuronal cells from thapsigargin insult after transfection with mSOD1 (G93A). mSOD1 (G93A) (green), NeuN (red), and merged images were monitored under confocal microscopy. Hoechst stain shows nuclei (blue). Expression of PDI significantly decreased apoptotic cell death in rat primary cortical neurons induced by thapsigargin, whereas SNOC significantly prevented this beneficial effect of PDI. Treatments: G93A or G, mSOD1 (G93A). T thapsigargin, S SNOC, P PDI. Values are mean + SEM, n =4. *P <0.01, **P < 0.001