The UC Irvine School of Medicine has finished a study that marks a first in medical research. The team, led by Tallie Z. Baram of the pediatrics department, has found that short-term, early-life stress can lead to an impaired memory and a decline in cognitive ability during middle age.
This study is significant because it has been the first to show evidence linking childhood stress to middle-age memory problems. It has been long suspected by researchers that both genetics and environment contribute to progressive brain deficits, but only genetic factors have been thoroughly studied.
The study was conducted on lab rats. The control group pups were given normal levels of nesting materials, while the experimental group had their nesting materials limited; this led to visible childhood stress for these latter pups. However, all signs of this early-life stress in the experimental group disappeared by adulthood.
As these rats grew, they began to show symptoms of memory loss generally associated with old age. It became clear that two forms of memory, both involved in the part of the brain called the hippocampus, were severely but selectively impaired.
‘We have very strong evidence that this is an anatomic change,’ said postgraduate researcher Eniko Kramar.
Published results in the Journal of Neuroscience state that early life stress leads to deterioration of cell-signaling in the hippocampus, which is involved in learning, storing and recalling memories.
Thus far, there have been mixed reviews to these findings. Most researchers are not surprised, since environment has generally been thought to influence mental health, although conclusive evidence, as found in the study, had yet to be found.
However, the significance from this study is due to the finding that the stress-related disorders stopped during the rats’ young adulthood and resurfaced 10 months later when the rats reached middle age.
This is shocking because once the symptoms occurred, the mental decline of the experimental rats was more rapid than the control group’s mental decline at an older age. These symptoms can lay dormant since the damage has already been done, which was not previously suspected.
The research conducted tells us nothing new about raising children, but gives more reasons to nurture them. Abuse, neglect, divorce and job changing can lead to childhood stress. Studies like these warn us that there are more fallouts to childhood stress than we had anticipated. This study is especially eye-opening because it reveals that the symptoms of memory loss can be hidden until middle age.
This research can be used to isolate the molecules that cause deficits, and eventually lead to a treatment to lessen the effects of the memory loss later in life.

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