Figure 2. Demyelination and microglia/macrophage activation in the midline of corpus callosum after six weeks of cuprizone exposure in the different diet groups.

The mice receiving a diet deficient (<50 IU/kg) or low (500 IU/kg) in vitamin D₃ content are extensively demyelinated, and the density of activated microglia and macrophages is high. The mice receiving a diet with higher vitamin D₃ content (6200 or 12500 IU/kg), are significantly less demyelinated (p = 0.004), and the density of activated microglia and macrophages is significantly lower (p = 0.001). All images at 40×.