title: Myelin impregnation: an improved Golgi-Cox modification.
abstract: Optic tecta of goldfish were coated with egg yolk and immersed for only one week in one of the following impregnation fluids: a) Solution A + B; A = 1 g K2Cr2O7 and 1 g HgCl2 boiled for 15 min in 85 ml distilled water and allowed to cool; B = 0.8 g K2Cr2O4 and 0.5 g KWO4 dissolved in 20 ml distilled water. b) Solution A + B two volumes diluted with boiled distilled water. c) Solution A + B four volumes diluted with boiled distilled water. Each tectum was immersed 6 hr in 100 ml distilled water containing 0.5 g LiOH and 15 g KNO3, washed 18 hr in 500 ml 0.2% acetic acid, dehydrated with ethanol, and embedded in low viscosity nitro cellulose. Sections were cut at 100 micron with a rotary microtome after clearing with cedarwood oil. Methods b) and c) have two advantages compared with method a), the original Golgi-Cox method. First, more cells are impregnated, especially in the layers extending 200-400 micron below the surface, and dendrites as well as unmyelinated axons are well impregnated. Second, myelin sheaths are impregnated and can be recognized by their peculiar chain-like appearance. The described Golgi-Cox modification offers an appropriate method to study the morphology of superficially located nervous tissue.
mesh_terms: D000818:Animals; D001369:Axons / Q000032:analysis; D006054:Goldfish; D006652:Histological Techniques; D009186:Myelin Sheath / Q000032:analysis*; D009474:Neurons / Q000032:analysis*; D013194:Staining and Labeling / Q000379:methods*; D013477:Superior Colliculi / Q000166:cytology