Scientists found traces of Alzheimer’s in elderly chimpanzees

© Illustration RIA Novosti . Alina Polyanina Plaques of beta-amyloid in nerve cellScientists found traces of Alzheimer’s in elderly chimpanzees© Illustration RIA Novosti . Alina Polyanina

Biologists have found traces of plaques of beta-amyloid in the brains of elderly chimpanzees that pointed to the fact that Alzheimer’s can affect not only humans, but its closest relatives in the animal world, according to a paper published in the journal Neurobiology of Aging.

«Unfortunately, we are not yet able to understand the consequences of the accumulation of this debris in the nerve cells of monkeys. These specimens, and our colleagues collected over several decades and no one did any systematic observations and have not watched any changes in behaviour and intellectual abilities of animals,» says Mary Ann Riganti (Mary Ann Raghanti) from the University of Kent (UK).

It is believed that Alzheimer’s is caused by the accumulation in neurons of pathogenic substances, the protein beta-amyloid. It is formed from «scraps» of the APP protein, which is involved in the processes of repair of the damaged neurons and links between them. Irregularities in the processing of the molecules of this protein leads to the appearance of plaques of beta-amyloid and the destruction of nerve cells.

In the past two years, biologists have made considerable progress in understanding what causes this disease and what she is. For example, recently scientists have found that Alzheimer’s may be contagious, found that plaques of beta-amyloid may be an important part of the innate immune system, and found several promising treatments.

These findings, as noted Raghani, as well as the similarity of beta-amyloid prions with «mad cow disease», has forced many scientists to look for analogues of the disease Allgamer other living beings. Their discovery would help scientists to get closer to the reveal of her roots and would accelerate the development and testing of drugs that are now checked for transgenic rodents whose brain doesn’t work that way, as a person.

Raghani and her colleagues found that plaques of beta-amyloid is quite often appear and accumulate in the nervous system common chimpanzees, the closest relatives of man, studying two dozen samples of the brain of the apes, died at the age of 37 to 62 years in various British nurseries primates in the last 20-30 years.

Cut small pieces of bark and underlying layers of the brain, scientists have discovered quite a lot of «balls» beta-amyloid and glued strands of the Tau protein, another alleged culprit in the development of Alzheimer’s disease. They were present in the brain of two thirds of the primates, and they contained significantly more nerve cells in older chimpanzees. It is confirmed that the scientists are dealing with traces of the disease Allgamer, not with the consequences of stroke or other severe brain injuries.

It is not yet clear is whether Alzheimer’s disease to develop problems with memory and mental acuity in monkeys – like watching monkeys have never been conducted. On the other hand, the owners of chimpanzees, samples whose brain was studied by the biologists, there was the fact that they suffered from the typical effects of development of senile dementia.

It is, as scientists believe, may indicate that the accumulation of plaques of beta-amyloid in nerve cells may not be the cause but one of the consequences and side effects of developing Alzheimer’s disease. Now scientists plan to test this by observing the behavior of older and younger chimpanzees and studying their DNA for the presence of mutations associated with the development of Alzheimer’s disease in humans.