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Zapping Brain Cells: 1: Fetal alcohol syndrome

POSTED 30 NOVEMBER 2006

I'll drink to the holiday drinking season!
As the holidays approach, the hustle at the malls is matched by the bustle at the bars, and chants of "bottoms up!" Boy with webbed eyes and sad demeanor stares into camera with beckoning lookarise from every street corner. Seriously, with so much alcohol greasing American gullets during the holidays, the Why Files got to thinking about ethyl alcohol, AKA booze. Ethyl alcohol or ethanol is the number-one drug of abuse. In the United States alone, it causes an estimated 100,000 premature deaths, and carries an annual cost of $185 billion. The sauce also gets blamed for a big proportion of violent crime.

This child shows the typical facial features of FAS, including a small brain, small opening of the eye, a small nose, and long span between nose and upper lip. Photo: Courtesy Kathleen Sulik (see " Genesis of Alcohol-Induced ..." in the bibliography)

But alcohol can also harm the unborn: Fetal alcohol syndrome affects roughly 1 percent of American births. According to the American Academy of Family Physicians, "Fetal alcohol syndrome is a group of problems in children born to mothers who drank alcohol during their pregnancy. These babies are usually small and underweight. They often have birth defects such as delayed development and, as they grow older, they may have behavior problems. The most serious list of problems associated with having fetal alcoholism spectrum disorderproblem is mental retardation." Fetal alcohol syndrome (FAS) is the biggest preventable cause of mental retardation, and studies find a substantial rate of psychiatric disorders among adults born with FAS.

Source: FASD Center for Excellence, University of Washington

(Scientists also speak of "fetal alcohol spectrum disorder," a broader term for ethanol's pre-birth damage to the body and brain. While acknowledging that the effects of alcohol vary according to when and how much the pregnant mother drinks, we'll stick to the better-known "fetal alcohol syndrome" in this discussion.)

For years, some researchers have warned that any alcohol exposure raises the danger of FAS, but the damage process remained obscure. Since 2000, however, it's become clear that much of the damage results from a distortion of the natural process of "programmed cell death," or apoptosis.

Apoptosis in 200 words or less
In five steps, round cell structure progresses to shapeless blobApoptosis was first described in the 1970s, when scientists noticed old cells dying without causing the typical burst of inflammation. Eventually, scientists realized that these cells were triggering an internal mechanism that caused them to break up so their contents could be recycled.

A damaged cell may undergo apoptosis if it is unable to repair genetic errors. This is how apoptosis protects the body against cancer. Diagram: NIH

Apoptosis is crucial to normal development. It prunes out tumor cells, immune cells that would otherwise attack the body and neurons that fail to connect with other brain cells. "It's a natural way of getting rid of old cells when new cells are being formed," says John Olney, a professor of psychiatry at Washington University in St. Louis.

Apoptosis is a quiet form of suicide. While necrotic cell death releases chemicals that can inflame nearby cells, apoptosis spares them. But because apoptotic cells quietly disappear within a day or so, programmed cell death is hard to study: You almost need an eyewitness to know it occurred.

How does apoptosis cause fetal alcohol syndrome?

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