FRIDAY, July 18 (HealthDay News) -- Exposure to alcohol prenatally could specifically be harmful to neurotrophins, peptides which are involved in the growth and development of the fetal brain, a new study shows.

Post-natal environment may temper some of that damage, but not all of it, the researchers added.

"Neurotrophins are produced in the nervous system and are critical for normal development of the brain," Robert F. Berman, corresponding author of a study appearing in the October issue of Alcoholism: Clinical and Experimental Research, said in a news release from the journal. "Neurotrophins also play important roles in learning and memory, and contribute to the repair of the brain following injury or stress."

Twenty-two pregnant rats were divided into groups receiving no alcohol, "low" amounts of alcohol, or "high" amounts of alcohol.

Baby rats were weaned then placed in one of three environments: isolated, social or enriched. Previous research by the same team had found that alcohol-exposed infant rats that were raised in enriched environments showed improvement in their motor function, learning and memory.

Here, prenatal alcohol exposure increased levels of brain neurotrophins in adult rats. But while an enriched environment reduced neurotrophin levels in some areas of the brain, other areas were unaffected.

"Our results did not support our hypothesis that the beneficial effects of early environmental enrichment in rats exposed prenatally to alcohol were mediated directly by the three neurotrophins we examined in four specific brain areas," said Berman, a professor of neurological surgery at the Center for Neuroscience at the University of California at Davis.

More information

Visit the U.S. Centers for Disease Control and Prevention for more on fetal alcohol syndrome.