Researchers examined stranded animals for the presence of the brain pathology.
Alzheimer's disease is a degenerative disorder that destroys human brain cells. It leads to a decline in mental function, affecting memory, thinking, language, and behavior. In Alzheimer's disease, changes in the chemistry and structures of the brain hinder the ability to process, store, and retrieve information.
However, a recent study discovered that the brains of dolphins exhibit typical symptoms of Alzheimer's disease.
The study, which is published in the European Journal of Neuroscience, included five different species-Risso's dolphins, long-finned pilot whales, white-beaked dolphins, harbour porpoises, and bottlenose dolphins-and found that four animals from different dolphin species had some of the brain changes associated with Alzheimer's disease in humans.
The authors of the study confirm that the findings could support the 'sick-leader' theory, in which an otherwise healthy pod of animals ends up in dangerously shallow waters after following a group leader who has become confused or lost.
"I have always been interested in answering the question: Do only humans get dementia?" said Frank Gunn-Moore, a neurobiologist at the University of St Andrews in Scotland.
"Our findings answer this question as they show potential dementia associated pathology is indeed not just seen in human patients."
"This study is also a great example of different research institutes and different branches of the life sciences working together."
"We were fascinated to see brain changes in aged dolphins similar to those seen in human ageing and Alzheimer's disease," said Professor Tara Spires-Jones of the University of Edinburgh. "Whether these pathological changes contribute to these animals' stranding is an interesting and important question for future work."