Published in The Times England,a newspaper from UK Dr. Maria Carolina Iradi was interviewed about her research. — the article reads:
Tell-tale signs of Alzheimer’s disease have been found in dolphins – the first clear evidence of the condition in a wild animal. The cetaceans, who died after they were washed up on the coast in Spain, had the same twisted strands and protein clusters in their brains as human patients with the devastating condition.
Scientists say that it is extremely rare to find both these changes in the brain of any animals other than humans. They say finding the same physical changes in dolphins lends weight to a theory that developing dementia may relate to another feature which people and dolphins have in common – unlike much of the animal kingdom, humans and dolphins can survive for decades after their prime age for having children.
Simon Lovestone, a neuroscientist specialising in ageing at Oxford University and co-author of the research, said that the discovery was incredibly interesting and added: “It doesn’t happen very often you come up with a hypothesis from first principles and it seems to be right.”
Uncertainty clouds the causes of Alzheimer’s disease, but patients develop large numbers of abnormal clusters of chemically “sticky” proteins, known as plaques, in the brain along with twisted fibres of a protein, known as tau tangles.
The presence of both in samples taken from the brains of dolphins stranded in Spain was discovered by Maria Iradi, a researcher in the United States. She was investigating whether degeneration in the brain might affect the way the mammals use echolocation to navigate.
She took her findings to Frank Gunn-Moore, a biology professor at St Andrews University, and his wife Danielle, a researcher at Edinburgh University. The couple have previously shown that cats develop brain problems similar to those of human Alzheimer’s sufferers after one of their own cats fell ill.
When Professor Gunn-Moore heard a lecture by Professor Lovestone predicting killer whales would show signs of Alzheimer’s disease because of their relatively long life, he approached him with the dolphin data.
They have since joined forces to publish the details in a journal, Alzheimer’s & Dementia, concluding: “almost uniquely other than in man, sea mammals and cats might have Alzheimer’s disease-like neurodegeneration.” They are also advertising for a researcher to examine the brains of dolphins and other sea mammals collected in the UK for more evidence.
Professor Lovestone said: “This doesn’t take us to doing experiments on dolphins. But Alzheimer’s disease research has been substantially delayed by the inadequacy of animal models. We really do not have good mouse models of Alzheimer’s disease and that is hugely, hugely important.”
He also has a theory that insulin plays a part in people living longer and developing Alzheimer’s. By changing insulin-signalling in animals such as flies and worms, he said, scientists could extend their life.
He said: “I have this theory that maybe the reason we live quite a long time is we have maybe not got very good at insulin-signalling, which makes us vulnerable to both diabetes and Alzheimer’s disease.”
Amy Dalrymple, head of policy at Alzheimer Scotland, said: “This is an exciting step forward for dementia research, which could provide an important basis for future studies.”
Professor Gunn-Moore will discuss the findings at Alzheimer Scotland’s Christmas lecture at The Hub in Edinburg on Thursday, December 14.
Plaques and tangles
Alzheimer’s disease is the most common cause of dementia and it affects almost 60,000 people in Scotland.
Most people who have the condition diagnosed are over 70 years of age. In the disease, brain cells and their connections slowly break down, affecting how patients cope with daily life.
This exact cause is unknown, although age, other family members developing Alzheimer’s, suffering heart disease and diabetes all raise the risk of developing the condition.
Scientists have studied the brain tissue of patients. They know that abnormal clusters of protein build up between nerve cells (plaques) and that dead and dying nerve cells contain twisted strands (tangles) of a different protein.
These plaques and tangles are the prime suspects in the debate about what disrupts connections in the brain of Alzheimer’s patients and causes brain cells to die.
It is thought that such changes in the brain begin years or even decades before patients develop obvious symptoms.
Other articles relating to Dr. Iradi’s research can be found at: