MONDAY, April 4, 2005 (HealthDay News) -- A study in rats suggests fetal exposure to alcohol may upset the body's circadian clock as children mature into adulthood.
Rat pups given alcohol during a period of rapid brain development showed major changes in these 24-hour rhythms as adults, according to a Texas A&M University study.
The pups received alcohol amounts that simulated several nights of binge drinking by a pregnant woman. The pups were given the alcohol shortly after birth, a period of rapid brain development that the researchers say matches the brain development of human fetuses in the third trimester of pregnancy.
When they became adults, rodents exposed to alcohol as pups showed a number of changes in circadian rhythm compared to normal rats. For example, the alcohol-exposed rats woke up earlier each night (rats are nocturnal) than normal rats.
And in the absence of a normal light-dark cycle, the alcohol-exposed rats became active 30 minutes earlier each day while normal rats became active about 20 minutes later each day.
This is the first study to show that alcohol exposure during brain development might affect circadian rhythm, according to researcher Dr. David J. Earnest of Texas A&M University Health Sciences Center.
The study may help explain why many children and adults with Fetal Alcohol Syndrome suffer from altered sleep/wake cycles, hyperactivity disorders, attention deficit and other behavioral problems, the researchers said.
The study was presented April 3 at the Experimental Biology meeting in San Diego.
The U.S. National Institute of Mental Health has more about biological clocks.