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Bottlenose dolphins in Florida. (Wendy Noke Durden via SWNS)<\/p>\n
By Stephen Beech<\/strong><\/p>\n Stranded dolphins<\/a> may have dementia, suggests a new study.<\/p>\n The marine mammals could be suffering from a form of Alzheimer\u2019s disease when they get washed up on beaches, according to scientists.<\/p>\n They say the debilitating condition may be triggered by naturally occurring cyanobacterial toxins, which may also cause dementia in humans.<\/p>\n Finding a beached dolphin or whale<\/a> is one of the most distressing occurrences for nature lovers<\/p>\n Researchers have been trying to work out why marine mammals become stranded on shore in the first place.<\/p>\n A group of American scientists have come up with an unusual hypothesis: just as adult humans with dementia are sometimes found wandering far from their home, perhaps dolphins become similarly disoriented by suffering from a form of Alzheimer\u2019s disease.<\/p>\n Beta-amyloid pathology in a stranded dolphin brain; g: hyperphosphorylated tau protein in the brain of a stranded dolphin. (David Davis via SWNS)<\/p>\n By Talker<\/p>\n In the case of marine mammals, the researchers say it appears that Alzheimer’s-type neuropathology and disorientation may result from “chronic exposure” to toxic molecules produced by cyanobacteria.<\/p>\n Studies of villagers on the Pacific island of Guam show that chronic dietary exposure to cyanobacterial toxins is associated with misfolded tau proteins and amyloid plaques characteristic of Alzheimer\u2019s disease.<\/p>\n Scientists say the cyanobacterial toxin BMAA, as well as 2,4-Diaminobutyric acid (2,4-DAB), and N-2-aminoethylglycine (AEG), have been found to be extremely toxic to neurons.<\/p>\n They explained that BMAA triggers Alzheimer\u2019s-like neuropathology and cognitive loss in animals.<\/p>\n The toxins can be “biomagnified” up the food chain in the marine ecosystem, according to research published in the journal Communications Biology<\/a>.<\/p>\n A study of 20 common bottlenose dolphins<\/a> stranded in the Indian River Lagoon in eastern Florida showed that their brains contained BMAA and 2,4-DAB.<\/p>\n Dr. David Davis is examining neuropathology using a digital Huron TissueScope LE at the Brain Chemistry Labs. (Paul Alan Cox via SWNS)<\/p>\n By Talker<\/p>\n Co-author Dr. David Davis said: “Dolphins stranded during the summer cyanobacterial bloom season contained 2,900 times the concentration of 2,4-DAB than those from non-bloom seasons.<\/p>\n “Brain neuropathology similar to Alzheimer\u2019s patients, including beta-amyloid plaques and hyperphosphorylated tau proteins, was found in the dolphin<\/a> brains.<\/p>\n “In addition, TDP-43 protein inclusions characteristic of a particularly severe form of Alzheimer\u2019s were also found in the dolphin brains.<\/p>\n “During bloom seasons, the same dolphins showed 536 differentially expressed genes associated with Alzheimer\u2019s disease.”<\/p>\n The duration of cyanobacterial blooms is increasing with climate warming and nutrient inputs associated with agricultural runoff and sewage discharges, say scientists.<\/p>\n Comparative Alzheimer’s pathways in dolphins in bloom season. (David Davis via SWNS)<\/p>\n By Talker<\/p>\n And cyanobacterial-laden waters have often been released down the St. Lucie River from Lake Okeechobee into the Indian River Lagoon.<\/p>\n<\/p>\n
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