Figure 8

The protective effect of NAD⁺ and Wld^S are additive. (A) Dissociated midbrain cultures from both WT and Wld^S mice were pretreated with NAD⁺ 24 hours before addition of 2 μm MPP⁺. (B) Quantification of TH+ cell bodies and (C) TH+ neurites show that NAD⁺ pretreatment was more effective in protecting Wld^S neurites from MPP⁺ versus untreated Wld^S cultures. (D) NAD⁺ dose response curve showing that the protection seen with 1 mM NAD⁺ is maximal. Addition of 10 mM NAD⁺ before MPP⁺ treatment induced 50% cell death in dopaminergic neurons (data not shown). Data are normalized to control cultures and denote the mean ± SEM of representative determinations made in three separate cultures. *p < 0.05; **p < 0.001.