Study Explores Alzheimer’s Disease in Chimpanzees

Understanding Alzheimer’s Disease

Alzheimer’s disease, a form of dementia, significantly impacts cognition, behavior, and memory. It is a progressive and debilitating condition that currently has no cure. A formal diagnosis of Alzheimer’s occurs when dementia is accompanied by two specific brain abnormalities: amyloid plaques and neurofibrillary tangles. These amyloid plaques form when amyloid-beta peptides misfold and become sticky, while neurofibrillary tangles arise when tau proteins twist into long filaments.

Chimpanzees and Alzheimer’s Disease

Traditionally, the development of Alzheimer’s disease has only been documented in humans. However, a recent study published in Science indicates that elderly chimpanzees may exhibit similar signs of Alzheimer’s. Anthropologist Mary Ann Raghanti investigated the brains of 20 chimpanzees aged 37 to 62 years, which is roughly equivalent to a human age of 120 years, for neurochemical indicators of Alzheimer’s.

Study Findings

The findings revealed that 13 of the chimpanzees had amyloid plaques, and four exhibited neurofibrillary tangles, which are typically associated with advanced stages of Alzheimer’s in humans. Although it cannot be definitively stated that these chimpanzees had Alzheimer’s disease—since they were not assessed for cognitive or behavioral changes while alive—the presence of the plaques and tangles strongly suggests a potential link to the disease.

Future Research Directions

To confirm these findings as indicative of Alzheimer’s disease, additional studies are necessary, particularly involving living chimpanzees. Given the limitations surrounding research on chimpanzees, future investigations may focus on areas such as sleep disorders, memory loss, disorientation, and socially inappropriate behavior. Furthermore, studying Alzheimer’s in chimpanzees could offer valuable insights for understanding the disease in humans, given the close biological relationship between the two species.

References

Alzheimer’s Association. (2017). What is Alzheimer’s? Retrieved from http://www.alz.org/alzheimers_disease_what_is_alzheimers.asp
Cross, R. (2017). Elderly chimps may get Alzheimer’s, renewing interest in studying these animals. Science. DOI: 10.1126/science.aan7152
Written by Seema N. Goolie, BSc