The latest news published in the Journal of Neuroscience revealed a link between stress and short term memory loss in elderly people. As people age, it’s normal for people to experience varying levels of decline in memory. The researchers from the University of Iowa investigated how exposure to stress can cause changes in the cognitive behavior of elderly individuals.
Here are the Details of the Study
The study was conducted on young and old rats that were divided into two groups. The researchers measured the level of stress hormone, called as corticosterone, in both these groups. The hormone corticosterone works similarly to the stress hormone, cortisol, in humans. After measuring the levels of stress hormone in rats, the researchers analyzed the cells located in the prefrontal cortex region of the rats. This region of the rat’s brain is primarily involved in short-term memory.
What Was The Result?
Researchers found that older rats with high levels of the stress hormone, corticosterone, had scarcer connections between the cells located in the prefrontal cortex region as compared with the older rats with lower levels of corticosterone. However, when examined in younger rats, it was found that the connections between the cells in the prefrontal cortex region were not altered by the impact of stress. The connections help us to process, store, and recall information and with aging and prolonged exposure to stress hormone, these connections can shrink and disappear.
According to a professor at Stanford University, Robert Sapolsky, “Older animals with elevated amounts of stress hormones in their blood were found to have worn-out or older frontal cortex as compared to animals with lesser amounts of stress hormones.” Thus, he concluded that stress works to accelerate aging in the primary region of the brain, i.e. the prefrontal cortex region. Although Sapolsky was not involved in this study, he is highly knowledgeable of the negative effects of prolonged stress.
The study author Jason J. Radley, of the University of Iowa, also found that older animals with elevated amounts of stress hormone performed badly in a test as compared to older rats with lower amounts of the stress hormone. This test was a part of the study where the older rats were required to make use of their short-term memory to trace food within a maze.
Radley further states that although stress is one of the leading reasons of memory lapses in adults during aging, there are other factors too that affect a decline in cognitive ability. Nevertheless, he concludes that the research has indicated that there are much more widespread negative effects of stress hormones on the brain than the researchers earlier assumed.