NEW HAVEN, Conn. (WTNH) – A Yale-lead study has found that early exposure to nicotine can trigger widespread genetic changes that affect the formation of connections between brain cells long after birth.
According to researchers, the finding helps explain why maternal smoking has been linked to behavioral changes such as attention deficit and hyperactive disorder (ADHD), addiction, and conduct disorder. Nicotine does this by affecting a master regulator of DNA packaging, which in turn influences activity of genes crucial to the formation and stabilization of synapses between brain cells.
“When this regulator is induced in mice, they pay attention to a stimulus they should ignore,” said Marina Picciotto, the Charles B.G. Murphy Professor of Psychiatry, professor in the Child Study Center and the Departments of Neuroscience and Pharmacology, and senior author of the paper.
Picciotto’s lab found that mice exposed to nicotine during early development did indeed develop behavioral problems that mimic symptoms of attention deficit disorder (ADD) in humans. Furthermore, it was found that these genetic changes were maintained even in adult mice. However, when researchers inhibited the master regulator these adult mice were calmer and no longer reacted to a stimulus they should ignore.
“It is exciting to find a signal that could explain the long-lasting effects of nicotine on brain cell structure and behavior,” Picciotto said. “It was even more intriguing to find a regulator of gene expression that responds to a stimulus like nicotine and may change synapse and brain activity during development.”