14 DAY TRIAL // University of Pittsburgh investigators determined in a new lab study conducted on unsuspecting rats that the adolescent brain is more susceptible to start suffering from conditions such as depression and addiction because it is undergoing a continuous process of development.
The work implies that people's chances of developing these disorders decrease as they age, once their brains are fully developed. The study was conducted on lab rats because their brain structures are weirdly similar to our own.
What researchers discovered is that the brains of adolescents tends to exhibit increased levels of neural activity in a region called the dorsal striatum (DS), which was linked with motivated learning, habit formation and decision-making in past studies.
When studying the rats, the team put the tiny rodents through a task in which the animals were trained to expect a reward. The scientists then cross-referenced neural activation patterns collected from adult and adolescent rats, PsychCentral reports.
What was interesting for the group to note was that the DS in the brains of adult rats did not become activated when the animals were faced with the prospect of winning a reward. This may also mean that they were less motivated to seek out that particular reward, experts hypothesize.
“The brain region traditionally associated with reward and motivation, called the nucleus accumbens, was activated similarly in adults and adolescents,” UP investigator and paper coauthor Bita Moghaddam, PhD, explains.
“But the unique sensitivity of adolescent DS to reward anticipation indicates that, in this age group, reward can tap directly into a brain region that is critical for learning and habit formation,” she adds.
Details of the research were published in the latest issue of the esteemed journal Proceedings of the National Academy of Sciences (PNAS). One of the most important conclusions was that both adult and adolescent rats reacted the same, but for different reasons.
Researchers were able to discover that age caused significant differences between neural responses in the two age groups. “A better understanding of how the adolescent brain processes reward and decision-making is critical for understanding the basis of these vulnerabilities and designing prevention strategies,” Moghaddam concludes.