Achievement

Chet Sherwood (PI) and colleagues have shown that the shrinkage of the brain that accompanies aging is unique to modern humans. Although more subtle age-linked neural changes have been observed in other species, there had never been a direct comparison with our closest relative, the chimpanzee. Using magnetic resonance imaging (MRI) Sherwood and colleagues compared the volumes of various brain regions from 87 adult humans ranging in age from 22 to 88 years with those from 99 adult chimps ranging from 10 to 51 years old. Results showed that in humans the volume of all brain structures decreased over the lifespan, whereas in chimpanzees the total brain volume, and it’s various parts, did not change significantly. This difference might be due to humans’ much longer lifespan. One potential cost of a larger brain and extended longevity in humans is a greater vulnerability to age-related neurodegenerative disease. These results were published in the PNAS.