That could mean a possible cause for behavioral problems such as attention-deficit hyperactivity disorder (ADHD), according to new research from the University of Alabama at Birmingham presented at Neuroscience 2010, the annual Society for Neuroscience meeting in San Diego.
Researchers showed that exposing rats to nicotine during pregnancy leads to a decrease in the number of new cells in the hippocampus portion of the brain, the area most connected to learning and memory.
"Failure to correctly incorporate newborn cells into the circuitry of the hippocampus — and the resulting disruption of neural pathways essential to learning — could account for some of the behavioral problems observed later in the lives of children of mothers who smoke during pregnancy," said Robin Lester, Ph.D., associate professor in the Department of Neurobiology and primary investigator. "These problems could include various cognitive deficits, learning difficulties, ADHD and an increased predisposition to drugs of abuse."
About 20 percent of women who smoke continue to do so throughout pregnancy, according to the World Health Organization (WHO). This may, in part, account for the prevalence of learning disabilities in children. Gestational nicotine exposure could provide a brain-circuitry mechanism that accounts for these behavioral problems.
"These studies should provide further reasons and/or warnings to expectant mothers that they should seek help in refraining from smoking during pregnancy," said Lester.