Figure 6

NAD⁺ protects dopaminergic cells and neurites from MPP⁺ toxicity. (A) NAD⁺ biosynthetic pathway [75]. (B) Dissociated WT dopaminergic cultures were pretreated with NAD⁺, Nmn, or Namn 24 hours before addition of 2 μm MPP⁺. Quantification of TH+ cell bodies and (C) TH+ neurites show that NAD⁺ and Nmn, but not Namn, protected cells and neurites from MPP⁺. Data are normalized to control cultures and denote the mean ± SEM of representative determinations made in three separate cultures. *p < 0.05, **p,0.01, ***p < 0.001.