(Ivanhoe Newswire) -- Cocaine abuse by young women of childbearing age is a growing problem. Now, a new study done on monkeys indicates babies exposed to cocaine in the womb may have long lasting brain changes -- especially males.

The research showed adult male monkeys who were exposed to cocaine in the womb appear to have altered function in dopamine receptors in their brains. Dopamine is similar to adrenaline. It affects brain processes that control movement, emotional response and ability to experience pleasure and pain. There are five known dopamine receptors. In humans, changes in them are associated with vulnerability to drug abuse.

Though the monkeys in the study experienced fetal cocaine exposure, they had no contact with the drug after birth. When the research team studied them at age 13, they found the male monkeys exposed to the drug in the womb yawned twice as much in a 30-minute period as the males who were not exposed.
 

Lindsay R. Hamilton, a graduate student at Wake Forest University in the laboratory of Michael Nader Ph.D., a professor of physiology and pharmacology, noted the increased yawning “suggested that these animals have either an increased number of the D3 (dopamine) receptors or the receptors have higher function or sensitivity.”

Studies of autopsies show that people who die of cocaine overdoses have higher numbers of D3 receptors. But the researchers involved in this study emphasize that differences they found in the monkeys don’t mean they will be more vulnerable to cocaine. They suggest more research is needed to see what affect cocaine exposure will have on male children after they grow up. Currently in the United States an estimated 1 million young adults were exposed to cocaine before birth.

SOURCE: Presented at the 2008 annual meeting of the American Society of Pharmacology and Experimental Therapeutics in San Diego, Calif., April 5-9, 2008