1. Low magnification view of Black-Gold staining of the hippocampus in the normal rat.

2. High magnification of previous figure reveals individual fine myelinated fibers traversing the hippocampus.

3. Black-Gold staining of myelin in the lateral striatum (left) and deep temporal cortex (right). Note that the small individual fibers appear black, while the large myelinated tracts such as the corpus callosum or penetrating fascicles appear brown. Light neutral red counterstain labels cell bodies.

4. Combined Black-Gold and malachite green respectively stain myelinated fibers and cell bodies in the normal rat hippocampus.

5. Conspicuous demyelination is seen in this survey view of the striatum of a rat exposed to 3-NPA.

6. High magnification of the striatum seen in previous figure. Note the deaggregation of the myelinated fascicles and absence of fine individual inter-fascicular fibers.

7. High magnification reveals myelin pathology, characterized by edematous varicosities of myelinated fibers in the rat hippocampus following exposure to kainic acid.

8. Parietal cortex of a rat following semi-chronic exposure to the anti-tuberculosis drug isoniazid reveals multiple pathologies including the presence of fragmented and edematous myelin, as well as phagocytes containing myelin debris.

9. Dark field illumination of the superficial parietal cortex of a normal rat reveals Black-Gold stained radial myelinated fibers in layers II and III, and fine parallel fibers in layer I. Crestyl violet acetate counterstain.

10. Dark field illumination of the outer blade of the dentate gyrus reveals the granule cell layer counter stained with malachite green. The surrounding myelinated fibers are stained with Black-Gold.

11. Combined dark field and blue epifluorescent illumination reveals both Fluoro-Jade B positive degenerating neurons and the fragmentation and loss of fine Black-Gold labeled myelinated fibers in the hippocampus of a rat exposed to kainic acid.

12. Combined dark field and ultraviolet epifluorescent illumination reveals the tip of a Fluoro-Gold injection at right. Note the presence of Fluoro-Gold labeled cells and the absence of fine myelinated fibers within the injection site, while the large penetrating myelinated fascicles remain throughout.