For decades, humans were thought to be the only species to develop Alzheimer’s disease. But in a study published this week in the journal Neurobiology for Aging, researchers revealed that they found signs of Alzheimer’s in the brains of 20 elderly chimpanzees. Specifically, they found amyloid-beta plaques and tau tangles — the two hallmark signs of Alzheimer’s in humans.
So, what does this mean for the search for a cure for Alzheimer’s disease? While the chimp brains in the study had the physical brain markers of Alzheimer’s disease, the symptoms of the degenerative disease have only been observed in humans. Researchers have theorized that chimps may have a protective factor that keeps them from exhibiting signs of Alzheimer’s like memory loss and loss of cognitive function. How this protective factor works is unclear, though researchers say it may have something to do with where the amyloid-beta concentrates in the chimpanzee brain. In the study, greater levels of amyloid-beta were found in chimps’ blood vessels, rather than in plaques, which is not what happens in human brains. Researchers are now studying neuron loss and inflammation in the chimp brains, which contribute to Alzheimer’s in humans. As researchers map out the differences and similarities in human and chimpanzee brains with signs of Alzheimer’s, they hope to understand why the human brain is so vulnerable to the disease.
Read the full study here.