Dietary exposure to an environmental toxin triggers neurofibrillary tangles and amyloid deposits in the brain | Proceedings of the Royal Society of London B: Biological Sciences

Neurofibrillary tangles (NFT) and β-amyloid plaques are the neurological hallmarks of both Alzheimer's disease and an unusual paralytic illness suffered by Chamorro villagers on the Pacific island of Guam. Many Chamorros with the disease suffer dementia, and in some villages one-quarter of the adults perished from the disease. Like Alzheimer's, the causal factors of Guamanian amyotrophic lateral sclerosis/parkinsonism dementia complex (ALS/PDC) are poorly understood. In replicated experiments, we found that chronic dietary exposure to a cyanobacterial toxin present in the traditional Chamorro diet, β-N-methylamino-L-alanine (BMAA), triggers the formation of both NFT and β-amyloid deposits similar in structure and density to those found in brain tissues of Chamorros who died with ALS/PDC. Vervets (Chlorocebus sabaeus) fed for 140 days with BMAA-dosed fruit developed NFT and sparse β-amyloid deposits in the brain. Co-administration of the dietary amino acid L-serine with L-BMAA significantly reduced the density of NFT. These findings indicate that while chronic exposure to the environmental toxin BMAA can trigger neurodegeneration in vulnerable individuals, increasing the amount of L-serine in the diet can reduce the risk.

Growth Of Toxic Algae Caused By Nitrogen From Pollution, Natural Sources including domoic acid Harmful To Marine Life And Human Health

MNT: Commonly found in marine waters off the North American West Coast, diatoms (phytoplankton cells) of the Pseudo-nitzschia genus produce a potent toxin called domoic acid. When these phytoplankton grow rapidly into massive blooms, high concentrations of domoic acid put human health at risk if it accumulates in shellfish. It can also cause death and illness among marine mammals and seabirds that eat small fish that feed on plankton. 
Domoic acid activates AMPA and Kainate glutamatergic receptors.