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. Author manuscript; available in PMC: 2009 Nov 29.
Published in final edited form as: Neurobiol Dis. 2009 Feb 26;34(3):417–431. doi: 10.1016/j.nbd.2009.02.009

Fig. 1.

Fig. 1

(a) Iron deposition in substantia nigra of rotenone-treated (A) and control rats (D) (20×). Iron deposits are indicated by dark blue reaction product (arrow-heads in panel A mark iron deposits; arrow shows dendritic arborization of dopamine neurons, with moderate loss of processes after rotenone treatment). The two central panels B, C are higher magnification images (40×) showing co-localization of the iron deposits and TH+ neurons. (b) Iron deposition in the substantia nigra of rotenone-treated (A) and control (C) monkeys (5×). Neuromelanin-containing neurons have light brown appearance. The central panel B is a higher magnification detail (40×) of a rotenone-treated monkey brain, where iron deposits can be seen inside and outside the neuromelanin containing neurons. (c) Colocalization of iron in both neurons and microglia. Panel A (40×) shows iron deposition within neuronal profiles (arrows) in a rotenone-treated rat. The section was also labeled for tyrosine hydroxylase (brown)as a maker for dopamine neurons. Although the iron-laden neurons do not stain for tyrosine hydroxylase, they are approximately the same size as the nearby dopamine neurons, indicated by asterisks. Panel B shows a higher magnification (100×) of an iron-laden neuron. Note the TH associated chromogen deposits (arrows).In panel C (40×),a degenerating iron-laden blue neuronal profile is shown (arrow). The degenerating neuron is surrounded by activated microglia (brown), which were identified by OX-42 immunoreactivity. At a later stage (panel D, 60×), punctate iron (arrows) is seen within a cluster of reactive microglia. (d) Panel A shows a high magnification image (100×) of a substantia nigra monkey neuron containing neuromelanin (brown) with diffuse iron deposition (blue). In panels B–D (100×), tyrosine hydroxylase positive neurons (brown) show blue iron deposition in a mitochondrial-like punctate pattern. (e) Iron deposits in microglia in monkey tissue (A, C 20×; B, D 100×). Tissue was stained for iron (blue) and microglia (brown) using an anti-CD68 antibody. Panels A and B show low- and high-power views, respectively, of iron and microglia in a control animal; note the melanized neuron in B. Panels C and D show iron and microglia in a rotenone-treated animal. There is activation of microglia and many of the microglia contain large iron deposits.