Adolescents are more likely to get hooked on drugs than adults, and two new studies are helping us understand why. Using both animal models and humans, researchers based in the U.S. have attributed these differing susceptibilities to addiction to the activity of a cellular molecule called eIF2α.
When its activity is increased, eIF2α negatively regulates the synthesis of new proteins, a process that previous research has shown is crucial for cocaine-induced change in behavior and the strength of connections between neurons across which information flows, or synapses. In addition, the rate of protein production in the brain is known to decrease with age. To find out how drugs might be affecting this system, the team headed by researchers at the Baylor College of Medicine in Texas began by putting adolescent and adult mice through a behavioral test that assessed their preference for a particular location.
Interestingly, cocaine significantly reduced the activity of eIF2α in the brain of adolescents, but not adults. As a result of this boost to protein synthesis, the connections between dopamine-producing neurons strengthened in the adolescent brains, enhancing the feeling of pleasure that cocaine gives and thus promoting addictive behaviors.