Localization of mercury in CNS of the rat. I. Mercuric chloride (HgCl2) per os

Adult Wistar rats of both sexes were exposed to mercuric chloride (HgCl2) through drinking water (20 mg HgCl2 liter-1 distilled water) ad libitum during an 8-month period. Animals were subsequently sacrificed by transcardial perfusion with glutaraldehyde. Coronal sections of the brain and cervical spinal cord were examined according to a histochemical technique based on a physical development process which renders mercury deposits visible. Mercury was found unevenly distributed in the brain and spinal cord with the heaviest deposits found within the motor nuclei of the rhombencephalon. In cerebral cortex, the highest concentration of mercury was found in the striate area. Mercury was also localized within the deep nuclei of cerebellum; none was found within Purkinje cells. A proportionately high amount of mercury was additionally found in the anterior horn motoneurons of the spinal cord. In general, mercury was found primarily within neurons, but it was also observed in the cytoplasm of glia and ependymal cells.