Black-Gold: a simple, high-resolution histochemical label for normal and pathological myelin in brain tissue sections

A novel haloaurophosphate complex called Black-Gold has been synthesized an d applied to localize myelin within the central nervous system. The techniq ue is tailored to studies using formalin fixed non-solvent processed tissue . The technique stains large myelinated tracts dark red-brown, while the in dividual myelinated axons appear black. This study demonstrates how this no vel tracer can be used to localize both normal and pathological myelin. Spe cific myelin changes associated with exposure to diverse neurotoxicants inc luding kainic acid, domoic acid, 3-nitropropionic acid, Fluoro-Gold and iso niazid are demonstrated and characterized. This study also demonstrates how Black-Gold can be combined with other histochemical markers including Niss l stains, retrogradely transported fluorescent tracers and fluorescent mark ers of neuronal degeneration. Advantages associated with the Black-Gold tec hnique include high resolution, high contrast, short histochemical processi ng time, and consistent reproducibility. (C) 1999 Elsevier Science B.V. All rights reserved.