Figure 6

PARP-1 regulates microglia-mediated amyloid β neurotoxicity. A, Representative microphotographs from wt neurons cultured alone, with wt microglia, or with PARP-1 ^-/- microglia exposed to 5 μM of Aβ for 36 h. Aβ caused death of neurons cultured with wt microglia, but not in neurons cultured alone or with PARP-1 ^-/- microglia. rAβ produced no neuronal death (not shown). Aβ-induced death of neurons in co-culture with wt microglia was blocked by the PARP-1 inhibitor PJ34 (PJ, 400 nM). B, Quantitative assessment of neuron survival, expressed relative to neurons cultured without Aβ or microglia (control). *p < 0.005; # p < 0.05 vs. control. n = 3.