Figure 2.

CR reduces small volume TH cell loss and enhances dopamine turnover in ghrelin WT but not KO mice. A, Overall cell volume for ghrelin WT mice showed a significant (p < 0.05) effect of MPTP administration but no effect of genotype or diet. B, Ghrelin KO mice showed no overall effect of diet, treatment, or genotype. The red dotted line represents the average cell volume of ghrelin WT MPTP-treated mice. When the cells were separated based on number and volume distribution as shown in C and D, the effect of CR is apparent. C, Ghrelin WT have a significant (p < 0.05) effect between ad libitum and CR cell volume in smaller (1000–2000 μm³) cells. There was no significant difference in the ghrelin KO mice (D). E, H, CR attenuates striatal DA loss in ghrelin WT but not ghrelin KO mice after MPTP administration. F, I, MPTP reduced DOPAC with no effect of genotype. G, J, CR reduced the elevation of the DOPAC/DA ratio in MPTP-treated mice compared with ad libitum, in ghrelin WT but not ghrelin KO mice. a, Significant compared with saline ad libitum controls. b, Significant compared with MPTP ad libitum controls.*p < 0.05, **p < 0.01. Data are represented as mean ± SEM (n = 6–10, two-way ANOVA, p < 0.05).