WEDNESDAY, March 14, 2007 (HealthDay News) -- Research in rats shows that a single, socially stressful situation may contribute to depression by killing new nerve cells in the hippocampus, the area of the brain that processes learning, memory and emotion.
In young rats, the stress of encountering older, aggressive rats didn't stop the creation of new brain nerve cells, the first step in a process called neurogenesis. However, this form of stress did prevent many new nerve cells from surviving, which left the young rats with fewer neurons for processing feelings and emotions.
This negative impact on neurogenesis could be a cause of depression, said senior study author Daniel Peterson, of the Rosalind Franklin University of Medicine and Science, near Chicago.
The study appears in the March 14 issue of The Journal of Neuroscience.
Stress-linked brain cell destruction doesn't happen immediately, however. "This is strong evidence that the effects of social stress on neurogenesis occur after a delay of 24 hours or more, providing a possible time window for treatment after acute episodes of stress," Henriette van Praag, of the Salk Institute for Biological Sciences, said in a prepared statement.
Peterson said the next step in this research is to try investigate how stress reduced the survival of the new nerve cells.
"We want to determine if antidepressant medications might be able to keep these vulnerable new neurons alive," Peterson said.
More information
The American Psychological Association has more about stress.
