Finkelstein_1988_Toxicology_49_165

The regional distribution of AChE inhibition by parathion in the human brain was examined in a comparative study of the brains of 2 victims of lethal parathion intoxication and 2 control brains matched for age and sex. AChE activity in discrete brain regions was studied by quantitative histochemistry of 40 microns-thick sagittal or coronal cryostat sections from the 4 brains. The inhibition of human brain AChE by parathion is regionally selective. The biggest decreases were observed in the cerebellum, some thalamic nuclei and cortex. Only a moderate decrease (10-30%) was observed in the substantia nigra and basal ganglia, while no effect at all was seen in white matter regions. Detailed knowledge of the brain regions affected by parathion poisoning may explain some of the clinical manifestations of organophosphate poisoning.