WEDNESDAY, Oct. 12, 2005 (HealthDay News) -- Emotional stress caused by parental loss, abuse or neglect during infancy may result in memory loss and cognitive decline in middle age.
That's the conclusion of a University of California, Irvine School of Medicine study in the Oct. 12 issue of the Journal of Neuroscience.
It's believed the study, conducted with rats, is the first to demonstrate that emotional stress at an early age can trigger a gradual deterioration of brain cell communication in adulthood. These cell-signaling problems occur in the hippocampus, an area of the brain involved in the collection, storage and recall of learned memories, the researchers said.
"The loss of cognitive function later in life is probably a result of both genetic and environmental factors," study leader Dr. Tallie Z. Baram said in a prepared statement. "While it is not yet possible to change a person's genetic background, it may be feasible to block the environmental effects, particularly of early life stress, on learning and memory later in life. These studies point to the development of new, more effective ways to prevent cognitive impairment later in life."
In this study, the researchers limited nesting material in cages where baby rats lived with their mothers. This lack of nesting material resulted in emotional stress for both the mother rats and their babies. Evidence of this stress seemed to disappear by the time the baby rats became young adults.
However, the researchers noted that by the time these rats hit middle age, they began to show problems in their ability to remember the location of objects they'd seen before and to recognize objects they'd encountered the previous day.
These memory deficits worsened as the rats grew older, compared with rats who hadn't been subjected to stress during their first week of life.
Further research revealed that the rats exposed to early life stress had normal electrical activity in their brain cells when they were young adults but that brain cell activity was faulty by the time they reached middle age. The changes in brain-cell activity were consistent with the rats' behavioral changes as they aged, the study said.
The American Academy of Family Physicians has more about age-related memory decline.