Children whose mothers smoked while pregnant might be more susceptible to abusing cocaine and methamphetamine as adolescents, said a University psychology faculty member who is studying the phenomenon.

Steven Harrod, an assistant professor of psychology, is focusing on the neurobiological correlates of fetal nicotine exposure, using a four-year, $1 million grant from the National Institute on Drug Abuse. He has hypothesized that such exposure makes adolescents, particularly females, more vulnerable to abusing brain-stimulating drugs.

"I'm interested in understanding the neurobehavioral changes that might happen as a result of nicotine exposure in the womb," said Harrod, who uses rodent models to mimic the rate and intensity of exposure. "Epidemiologists have previously shown that only 30 percent of female nicotine-dependent smokers actually quit smoking during pregnancy."

Harrod's model reproduces the brain spikes of nicotine exposure that mimic actual smoking behavior. He surmises that gestational nicotine exposure will later increase the stimulant effects of cocaine and methamphetamine in adolescent brains.

"Does that mean that every adolescent who was exposed to nicotine in the womb will go on to abuse such drugs? Of course not, but it could alter their neurotransmitters in such a way as to make them more vulnerable to psycho-stimulants if they ever experiment with them," Harrod said.

Neuroscientists have identified a motivational circuit in the brain that is fed by brain chemicals and which affects mood and reinforcement of behaviors. It's possible that fetal nicotine exposure might alter this circuit in a way that would reinforce drug-abusing behavior.

"If you're going to create some kind of pharmacotherapy to help adolescents who are abusing drugs, you have to understand all of the neurobiological variables," Harrod said. "This kind of basic research is aimed at trying to understand the complex world of drug-taking behavior.

"The reason I'm looking at adolescent drug use is because drug abuse doesn't start in adulthood--it begins during adolescence."

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