Brain Shrinkage is Unique to Humans
BBC has reported that brain shrinkage is unique to the human brain and does not effect our closest evolutionary relatives, chimpanzees. Currently, humans are the only known animals to suffer from age-related dementia, which is directly related to the shrinkage of our brains.
By age 80, the average human brain has lost 15% of its original weight. Scientists have determined that the weight loss is associated with the decline of neurons and in the connections between them. This decline also affects the brain’s ability to process thoughts and memories.
Researchers do not understand why our brains experience a loss of gray matter as we age. Chimp’s brains, which are three times smaller than a human brain, do not shrink with age.
“Because neurons cannot regenerate, aging [in his opinion] is just the stress of living long enough to lend a helping hand to some relatives,” says Dr. Sherwood from George Washington University.
Why should our intricate and intelligent brains be afflicted with such debilitating diseases as Alzheimer’s and brain shrinkage?
One reason for this brain shrinkage might be that human’s life spans are longer than other animals; therefore, we are more vulnerable to age related diseases simply because we live longer. It is no surprise that researchers found even more brain shrinkage in individuals with Alzheimer’s opposed to those without the disease.
View the study, Aging of the Cerebral Cortex Differs Between Humans and Chimpanzees, here.