- WASHINGTON (Reuters) -- Severe
stress can permanently affect an adolescent's brain, causing changes in
an area important for learning and memory, U.S. researchers reported on
Saturday.
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- The study, conducted using rats, suggests that teens
may not always bounce back from trauma and suggests that adolescents may
be more susceptible to permanent damage from stress than younger children.
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- Susan Andersen of Harvard Medical School and McLean Hospital
in Belmont, Massachusetts and colleagues found that rats exposed to stress
during adolescence -- by being kept alone in cages -- had lower levels
as adults of a key protein in the hippocampus, a brain region important
for learning and memory.
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- The protein, synaptophysin, is used to measure how many
brain cell connections are being made. Lower levels suggest reduced brain
activity.
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- Andersen's team told a meeting of the Society for Neuroscience
in New Orleans that their study was the first to show that stress during
adolescence affects adult brain cell connections.
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- Usually, in humans, synaptophysin levels peak between
the ages of 18 and 20. Anderson's team tested rats of comparable age.
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- The rats kept alone -- something very stressful for a
rat -- did not experience the normal increase in synaptophysin as they
reached early maturity.
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- "These data may suggest why early traumatic stress,
such as physical or sexual abuse or neglect, is associated with a decrease
in the size of the hippocampus in adulthood," McLean Hospital said
in a statement.
-
- "These pre-clinical data suggest that stress experienced
early in life alters the normal developmental trajectory of the hippocampus,
but that these changes are not apparent until later in life," said
Andersen.
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- http://news.reuters.com/newsArticle.jhtml?type=healthNews&storyID=37
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