Effects of maternal smoking continue long after birth ;
early exposure to nicotine can cause widespread genetic changes that affect the formation of connections between brain cells long after birth, a new study led by the University of Yale has found. The finding helps explain why maternal smoking has been linked to changes in behavior, such as attention deficit hyperactivity disorder, addiction and behavioral disorder.
Nicotine does this affect a master of DNA packaging regulator, which in turn influences the activity of genes crucial for the formation and stabilization of synapses between cells brain , according to the study published online May 30 in the journal Nature Neuroscience .
“When this control in mice, they pay attention to a stimulus that should ignore ‘induced’ said Marina Picciotto, the BG Murphy Professor Charles of Psychiatry, professor at the Center for Child Studies and the Departments of Neuroscience and pharmacology and lead author of the article.
An inability to concentrate is the hallmark of attention deficit hyperactivity disorder and other behavioral disorders that have been linked to maternal smoking and exposure to second hand smoke. However, scientists did not understand how early environmental exposure to smoking behavior could create problems years later.
Picciotto’s lab found that mice exposed to nicotine during early development indeed problems similar to behavior disorder symptoms develop attention deficit in humans. He then made an extensive exploration of the genome of mice exposed to nicotine and found higher levels of activity in a key regulator of histone methylation, a process that controls gene expression by changing the wrapping DNA around chromosomes. The researchers found that genes essential for the creation of brain synapses were strongly affected.
Furthermore, the scientists found that these genetic changes were maintained even in adult mice . However, when the researchers inhibited the master regulator of histone methylation these adult mice were quieter and did not react to a stimulus that should be ignored. In a final test, which activate the expression of this regulator in mice exposed to nicotine, and mice that mimicked the behavior attention deficit disorder exhibited.
“It is exciting to find a signal that could explain the long-term effects of nicotine on the brain cell structure and behavior,” Picciotto said. “It was even more intriguing to find a regulator of gene expression that responds to a stimulus such as nicotine and can change the activity of synapses and brain during development.”
This article was originally published on medicalxpress, Read the original article
Posted in: Neuroscience