Dolphins, like humans, have the potential to develop Alzheimer’s disease. The disease affects the brain, and is often associated with memory loss, space-time disorientation, and a decrease in cognitive skills. But scientists are still uncertain of what causes the disease in animals. Studies have shown that dolphins can develop the condition decades after their prime child-bearing years. In fact, a team of scientists believes that dolphins and humans may be unique in their ability to develop the disease.
Researchers looked at a variety of animal species, and compared their brains to those of people. They found signs of classic markers of Alzheimer’s disease in the brains of three dolphin species. These include abnormal protein fragments known as “tangles” that block communication between brain cells. It is believed that these abnormal proteins eventually kill the brain cells, and this is what causes the Alzheimer’s-like pathology in these creatures.
One of the biggest discoveries made in this study is the presence of the insulin signaling cascade, which sets off a series of complex chemical reactions. Insulin is responsible for controlling blood sugar levels, and it is thought that changes in insulin signalling in dolphins could trigger the disease. However, more research is needed before scientists can fully understand how this process works in these animals.
Several different researchers also studied the same dolphins, including a group from the University of Miami, which examined 14 different dolphins from Florida to Massachusetts. Their findings suggested that the dolphins’ brains accumulate two proteins related to Alzheimer’s: BMAA (b-methylamino-L-alanine) and beta-amyloid. Both of these proteins trigger the formation of plaques in the brain, which is the hallmark of Alzheimer’s disease.
Scientists from Scotland also worked with the University of Glasgow to identify Alzheimer’s-related changes in the brains of five different species of dolphins. These included white-beaked dolphins, harbor porpoises, and long-finned pilot whales.
Two scientists, Dr Mark Dagleish and Professor Frank Gunn-Moore, had not seen each other in over 30 years. A pub meeting in Edinburgh led them to collaborate on a study of the dolphins’ brains. While they are hesitant to suggest testing captive dolphins for Alzheimer’s-related changes, the team’s findings might offer a window into the disease’s development in these creatures.
The study was published in the European Journal of Neuroscience. It was the first time Alzheimer’s-like pathologies have been found in a wild species. Previously, the disease had been observed in captive mammals, including chimpanzees and monkeys.
The authors caution that the study’s findings do not mean that the dolphins have developed Alzheimer’s, and that it is unlikely they will in the future. Instead, they say the dolphins’ findings might help scientists get closer to developing a treatment for the disease. Hopefully, more studies will be conducted on other long-living creatures, such as the whales and dolphins that inhabit the oceans of our planet.
As the first to observe a species of animal that has Alzheimer’s-like pathologies, the dolphins are now a step closer to the truth about the disease. This may lead to advances in Alzheimer’s research, and help scientists come closer to treating this illness.