Alcohol late in pregnancy may create an 'old' baby

Texas A&M study says brain appears to age

By TODD ACKERMAN
Copyright 1997 Chronicle Science Writer

A mother's alcoholic binge in late pregnancy could make the unborn child
or at least his or her brain old before its time, according to Texas A&M
University scientists.

In studies of laboratory rats, the research team found that exposure to
high doses of alcohol during the equivalent of the last three months of
human pregnancy causes change in the animals' brains and behavior that look
a lot like old age.

"We are seeing behavioral changes such as fragmented sleep and short bouts
of activity reminiscent of changes associated with aging," said A&M
neurobiologist David Earnest, who led the study. "In essence, alcohol
exposure accelerates the aging of the biological clock in the brain that
controls daily or circadian rhythms."

Earnest's team also found alcohol permanently changed levels of an
important brain chemical associated with the regulation of those circadian
rhythms, which tell humans and other animals when to fall asleep and wake up.

Earnest, who studies the biology of circadian rhythms, described the
discovery in a paper presented Sunday at the annual meeting of the Society
for Neuroscience in New Orleans.

Alcohol abuse, the single biggest known cause of birth defects, contributes
to criminal and other antisocial behavior as well.

A recent study found 90 percent of people with fetal alcohol syndrome or
effects had mental health problems; 60 percent had had trouble with the
law; 60 percent had disrupted educations, 50 percent had been involuntarily
confined and 50 percent had been accused of inappropriate sexual behavior.

But because fetal alcohol syndrome wasn't discovered until 1973,
researchers still have only limited understanding of what areas of the
fetal brain and what associated behaviors in humans are specifically
affected by alcohol.

Earnest said further studies will be needed to understand whether fetal
alcohol exposure induces similar, longterm changes in human circadian
rhythms and what are the behavioral consequences of those changes.

Earnest's team examined the effects on the brain of high doses of alcohol
administered during the first few days after the rats were born, a period
during which rats' brains develop at the same rapid rate that occurs during
the last trimester of human pregnancy. The dose of alcohol was the
equivalent of two or three times the legal limit for humans.

Like humans in old age, the alcoholtreated rats began their activity
earlier each day and alternated between short intervals of sleep and
waking. In addition, they experienced declines in the chemical that spurs
and maintains cell functioning in the brain.

Earnest said that understanding whether specific changes in the brain's
biological clock are responsible for alterations in circadian rhythms and
the sleepwake cycle also should have important implications for human
mental health and performance. He noted, for instance, that sleep
disturbances are the secondleading cause of institutionalization of older
people.

Current studies are exploring whether genetically engineered cells could
provide a "fountain of youth" and restore normal circadian rhythms
especially normal sleepwake cycles in aged people.