Rats exposed to high doses of amphetamines at an age that corresponds to the later years of human adolescence display significant memory deficits as adults -- long after the exposure ends, researchers report.
The declines in short-term or "working" memory are most pronounced when the rats are exposed during adolescence, rather than as adults, the researchers found.
"Animals that were given the amphetamine during the adolescent time period were worse at tasks requiring working memory than adult animals that were given the same amount of amphetamine as adults," said psychology professor Joshua Gulley, who led the study with graduate student Jessica Stanis. "This tells us that their working memory capacity has been significantly altered by that pre-exposure to amphetamine."
"Adolescence is a time when the brain is continuing to develop into its mature form, so drug exposure during this critical period could have long-lasting, negative consequences," he said. "Our findings reveal that adolescents are particularly sensitive to the adverse effects of amphetamine on cognitive function and that these effects can persist well after drug use is discontinued."
Gulley and his colleagues will present their findings at the annual meeting of the Society for Neuroscience in Chicago.