The study, reported in the journal Neuroscience, found that amphetamine leads to changes in dopamine signaling. Dopamine is a neurotransmitter that plays a role in memory, attention, learning and feelings of pleasure.
“The dopamine system, which continues to develop throughout adolescence and young adulthood, is a primary target of psychostimulant drugs like amphetamine,” said University of Illinois psychology professor Joshua Gulley, who led the new research. “Changes in dopamine function in response to repeated drug exposure are likely to contribute to the behavioral consequences — addiction and relapse, for example — that abusers experience.”
Parallels between rat and human development make rats a worthy model for the study of human drug addiction, which often begins in adolescence, Gulley said.
“Rats exhibit many of the characteristics that human adolescents do. They tend to be more impulsive than adult rats; they tend to make more risky decisions,” he said. They also can engage in “addiction-like behaviors,” he said.