In order to investigate protein function in rat primary cortical neuronal cultures, we modified an adenoviral vector expression system and assessed the strength and specificity of the cytornegalovirus (CMV), rous sarcoma virus (RSV), and rat and human synapsin 1 (SYN1) promoters to drive DsRed-X expression. We also incorporated the woodchuck post-transcriptional regulatory element (WPRE) and a CMV promoter-enhanced green fluorescent protein (EGFP) reporter cassette. We observed that the RSV promoter activity was strong in neurons and moderate in astrocytes, while the CMV promoter activity was weak-to-moderate in neurons and very strong in astroCyteS. The rat and human SYN1 promoters exhibited similarbut weak activity in neurons, despite inclusion of the WPRE. We confirmed that the WPRE enhanced RSV promoter-mediated DsRed-X expression in a time-dependent fashion. Interestingly, we observed very weak SYN1-mediated DsRed-X expression in astrocytes and HEK293 cells suggesting incomplete neuronal-restrictive behavior for this promoter. Finally, using our adenoviral expression system, we demonstrated that RSV promoter-mediated Bc-X-L overexpression attenuated neuronal death caused by in vitro ischemia and oxidative stress. (c) 2006 Elsevier B.V. All rights reserved.