Vulnerability of dorsal root neurons and fibers toward methylmercury toxicity: a morphological evaluation

Journal Article · Thu Oct 01 04:00:00 EDT 1981 · Environ. Res.; (United States)

DOI:https://doi.org/10.1016/0013-9351(81)90194-8· OSTI ID:5705067

Yip, R K; Chang, L W

The selective and relative sensitivity of various components (dorsal root neurons, dorsal root fibers, and ventral root fibers) of the dorsal root ganglia toward methylmercury toxicity were investigated. Charles River rats were orally administered methymercury chloride at a daily dose of 2.0 mg/kg body wt for 8 weeks. Dorsal root ganglia (L/sub 1/-S/sub 1/) were examined with light and electron microscopy. Extensive Wallerian-like degeneration was observed in the dorsal root fibers while no significant changes were found in the dorsal root neurons and in the ventral root fibers at the light-microscopic level. At the electron-microscopic level, only minor and possibly reversible changes, such as increase in lysosomes, neurofilamentous proliferation, and disintegration of the Nissl substance, were observed in the neuronal cell bodies while severe and irreversible degenerative changes occurred in the dorsal root fibers. No remarkable pathological changes were observed in the ventral root fibers. Schwann cells became hypertrophied and transformed into actively phagocytosing macrophages. It is concluded that while the dorsal root ganglia are highly vulnerable to the toxicity of methylmercury, the relative sensitivity to the toxic impact is: dorsal root fiber > dorsal root neuron (nerve cell body) > ventral root fibers.

• Research Organization: Univ. of Arkansas, Little Rock
• OSTI ID: 5705067
• Journal Information: Environ. Res.; (United States), Journal Name: Environ. Res.; (United States) Vol. 26:1; ISSN ENVRA
• Country of Publication: United States
• Language: English

Related Subjects

560305* -- Chemicals Metabolism & Toxicology-- Vertebrates-- (-1987)
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ANIMAL CELLS
ANIMAL TISSUES
ANIMALS
BIOLOGICAL EFFECTS
BODY
CHLORINE COMPOUNDS
ELECTRON MICROSCOPY
HALOGEN COMPOUNDS
MAMMALS
METHYLMERCURY
MICROSCOPY
MORPHOLOGICAL CHANGES
NERVE CELLS
NERVE TISSUE
OPTICAL MICROSCOPY
ORGANIC COMPOUNDS
ORGANIC MERCURY COMPOUNDS
RATS
RODENTS
SOMATIC CELLS
TISSUES
TOXICITY
VERTEBRATES