THE ESSENTIAL
- Alzheimer’s disease is characterized by different symptoms in humans: memory problems, problems performing simple gestures, orientation in time and space, and cognitive functions. It might perhaps also affect certain cetaceans.
- Cetaceans such as dolphins, porpoises or whales are sometimes found stranded in groups on the coasts. The results of this study might provide an explanation for this phenomenon.
Researchers have analyzed the brains of three species of stranded dolphins. The latter presented the classic markers of human Alzheimer’s disease, according to the results of their study published in theEuropean Journal of Neuroscience.
The research team, made up of members of the Scottish universities of Glasgow, St Andrews, Edinburgh and the Moredun Research Institute, studied the brains of 22 odontocetes (species of cetaceans with teeth, such as the dolphin or the sperm whale , as opposed to baleen whales, baleen whales), all of which had washed up in Scottish coastal waters. These included five different species: Risso’s dolphins, pilot whales, white-beaked dolphins, harbor porpoises and bottlenose dolphins.
Alzheimer’s disease also affects the brains of dolphins
There, scientists looked for hallmarks of Alzheimer’s disease, including the formation of beta-amyloid plaques, phospho-tau accumulation, and gliosis (a change in the number of cells in response to damage to the central nervous system ). The results reveal that the brains of all the aged animals studied had beta-amyloid plaques.
Among them, three animals in particular – each from a different species – had beta-amyloid plaques as well as a number of other dementia-related signs in their brains, showing that some cetacean species can also develop the disease. Alzheimer’s type.
An explanation for the phenomenon of groups of stranded dolphins?
These results may provide a possible explanation for some mysterious stranding events in cetaceans. The study authors point out that these results might support the “sick leader” theory, according to which a group of animals, while healthy, can end up in dangerously shallow water following following a group leader who has become confused or lost, possibly due to Alzheimer’s disease.
Still, the study authors point out that more research needs to be done to better understand what’s happening to these animals and to confirm whether it’s the same Alzheimer’s disease that affects humans.
