Knockdown of NP1 by siRNA targeted against NP1 mRNA significantly protected against OGD-induced neuronal death. We have achieved >90% reduction in NP1 protein compared to scramble siRNA (shown in inset). LDH cytotoxicity and MTT cell viability (A-B) showed significantly less cell death in NP1-siRNA transfected WT cells vs. non-transfected cells following exposure to OGD (6 h). Data are expressed as percent LDH release normalized to normoxia control (mean ± SEM, n = 8; **p < 0.01 compared to control normoxia; +p < 0.01compared to OGD scramble siRNA group) C) TUNEL staining of cortical neurons transfected with either control scramble or NP1-siRNA revealed significant increase in the number of TUNEL (+ve) cells in scramble SsiRNA transfected cultures, which was significantly reduced in NP1-siRNA transfected neurons. Data are expressed as percent TUNEL/DAPI cells (mean ± SEM, n = 8; **p < 0.01 compared to control normoxia; +p < 0.01compared to OGD scramble siRNA group).