MPTP induces a similar deposition of ferric iron in Nrf2^−/− and HO-1^−/− mice.

<p>Iron precipitates were detected by DAB-enhanced Perls reaction followed by Nissl counterstaining. <i>A,</i> simplified scheme of a coronal section of midbrain showing the location of mouse dorsal and ventral substantia nigra on the left (SNc and SNr, respectively). The rectangle on the right side indicates the region shown in panels <i>D, E, F and G</i>). <i>B</i> and <i>C</i>, high magnification pictures of the boundary between SNc and SNr from wild type mice submitted to saline or MPTP treatments, respectively. Yellow arrowheads point some large Perls-negative cells with pale nuclei and dark nucleoli typical of dopaminergic neurons. Green arrowheads point small Perls-positive cells with picnotic nuclei typical of microglia. The red arrowhead points a Perls-positive microglial cell that has been drawn in the inset to show microgrial extensions. The large panels show representative fields of both SNc and SNr (location indicated in the rectangle of <i>A</i> panel), from saline-treated wild type mice (<i>D</i>), MPTP-treated wild type mice (<i>E</i>), MPTP-treated Nrf2^−/− mice (<i>F</i>), and MPTP-treated HO-1^−/− mice (<i>G</i>).