Morphine abuse during adolescence has multigenerational effects on brain

The research was presented at Neuroscience 2010, the annual meeting of the Society for Neuroscience, held in San Diego.

"Abuse of prescription pain relievers among adolescents -- girls as well as boys -- is a growing concern," said Elizabeth Byrnes, PhD, of Tufts University. "Unfortunately, the long-term consequences of female adolescent drug use, particularly on future children, are unknown. Our findings suggest that a mother's history of drug use may have a significant impact on her children and grandchildren, even if the woman was not using drugs at the time she got pregnant."

For this study, female rats were given morphine for 10 days during adolescence. The doses were similar to what an abuser of prescription narcotics might use. After a drug-free period, the females were mated with healthy males, and the first and second generation offspring were subsequently studied when they reached adulthood.

First generation male adult offspring demonstrated decreased sensitivity to the drug quinpirole, a chemical that mimics the reward chemical dopamine in the brain. They also found this same effect in the second generation male offspring.

Disruption of dopamine is associated with addiction and psychiatric disorders. "Our model could be used to help determine how substance abuse and other reward-related disorders are passed down through several generations," said Byrnes. "We are currently examining changes in the expression of particular genes in both the mother and her offspring to determine how these effects are transmitted," she said.

Research was supported by the National Institute on Drug Abuse.