Scientists from the University of Maryland, working with colleagues at the University of Wisconsin-Madison and the California National Primate Research Center, have discovered a brain circuit that appears to play an important role in the transmission of extreme anxiety from parents to their offspring.
Although anxiety disorders are consistently ranked among the top 10 causes of global disability and sickness by the World Health Organization, existing treatments are inconsistently effective or, in some cases, associated with significant side effects. Like other mental illnesses, anxiety disorders are heritable: Parents who are anxious are more likely to have children who suffer from extreme shyness, inhibition and anxiety. Yet the brain circuits underlying the intergenerational transmission of extreme anxiety have remained mysterious.
Leveraging recent advances in genetics and brain imaging, the new study, published in the Journal of Neuroscience, marks the first demonstration that connectivity within the central extended amygdala plays a role in the genetic transmission of extreme anxiety.
“We took advantage of earlier work that had painstakingly measured anxious temperament, individual by individual, in an extended family of nearly 2,000 individual monkeys,” said Alex Shackman, Ph.D., a professor in the Department of Psychology and Neuroscience and Cognitive Science (NACS) program at UMD, and a co-author of the study. “The large sample greatly increases our confidence in the replicability and robustness of these effects.”
Researchers used brain imaging techniques also used in human studies to look at the brains of young rhesus monkeys, who express anxiety in similar ways to human children. “This work provides invaluable new clues about the brain circuits to focus on in human patients, especially youth, and promises to accelerate the development of new treatments for early life anxiety,” Shackman said. Shackman leads several other ongoing brain imaging studies at the University of Maryland aimed at understanding the role of this circuitry in mood and anxiety disorders in adolescents and young adults.
The study was funded by the California National Primate Research Center, National Institutes of Health, University of California, and University of Maryland.
August 10, 2018