Related Experiment Video
Updated: Aug 23, 2026
Human Pluripotent Stem Cell Based Developmental Toxicity Assays for Chemical Safety Screening and Systems Biology Data Generation
Published on: June 17, 2015
Human brain disturbance by methylmercury poisoning, focusing on the long-term effect on brain weight
1Kumamoto University, Japan.
Abstract:
The long-term effects of the initial methylmercury exposure in the Minamata area were examined, with focus on brain weight. Comparisons were made between the brain weights of methylmercury-contaminated persons in the Minamata area (cases) and those of Japanese who suffered sudden or accidental death without brain disease (controls). Since over thirty years have passed since the outbreak of Minamata disease, subjects aged 30 or over at death were included in the analysis. The total number of cases was 417 (273 males, 144 females) and that of controls was 2,934 (2,174 males, 760 females). The data suggest that the brain weights from Minamata cases were reduced by 80 to 200g as compared to the controls. These results may indicate that methylmercury exposure led to a decrease of nerve cells (single cell necrosis), so-called "thinning out", in the brain cortex.
Insights
Long-term methylmercury exposure in Minamata significantly reduced brain weight in affected individuals. This neurotoxic effect may be due to nerve cell loss in the brain cortex.
Area of Science:
- Environmental Health
- Neurotoxicology
- Public Health
Background:
- Minamata disease, caused by methylmercury poisoning, has long-term health implications.
- Assessing the chronic neurological impact of methylmercury is crucial for understanding its persistent effects.
Purpose of the Study:
- To investigate the long-term effects of methylmercury exposure on brain weight.
- To quantify the reduction in brain weight among Minamata disease patients compared to a control group.
Main Methods:
- Comparative analysis of brain weights between methylmercury-contaminated individuals (cases) and a control group.
- Inclusion of subjects aged 30 and over at death, over 30 years post-outbreak.
- Analysis of 417 cases and 2,934 controls.
Main Results:
- Minamata cases exhibited reduced brain weights, ranging from 80 to 200g less than controls.
- Statistical significance in brain weight reduction was observed.
Conclusions:
- Methylmercury exposure is associated with a significant decrease in brain weight.
- The observed brain weight reduction may result from methylmercury-induced nerve cell necrosis (thinning out) in the brain cortex.
Related Concept Videos
01:03Long-term Depression
Calcium Ion Concentration Mechanism
If over time, all...
01:29Hepatic Encephalopathy