Patterns of brain activity associated with anxiety in monkeys are passed from parent to child, researchers report today (July 30) in the Journal of Neuroscience. The results could give clues to the heritability of severe anxiety in humans and how to treat it.
In the study, Ned Kalin of the University of Wisconsin School of Medicine and Public Health and colleagues studied the stress response and cortisol levels of 378 young monkeys after an intruder entered the animal cage. The researchers also took scans of the monkeys’ brains while the animals were anesthetized and found that the monkeys with greater stress responses had differences in brain activity in the extended amygdala compared with those that were less stressed.
The scans showed that, in stressed monkeys’ brains, two regions in the extended amygdala— the central nucleus and the bed nucleus of the stria terminalis—exhibited similar responses. When activity in one region was high, it was also high in the other region—and this heightened connectivity was passed on from parent to child, family trees revealed. The same brain regions have been implicated in anxiety in humans, Science News reports.
“We are continuing to discover the brain circuits that underlie human anxiety, especially the alterations in circuit function that underlie the early childhood risk to develop anxiety and depressive disorders,” Kalin tells Newsweek. “These findings are highly relevant to children with pathological anxiety and hold the promise to guide the development of new treatment approaches.”
The research “is still many steps away from knowing the best way to intervene,” Kerry Ressler, a psychiatrist and chief scientific officer at McLean Hospital in Belmont, Massachusetts and who was not involved in the work, tells Science News.
Study coauthor Jonathan Oler, an associate scientist at the University of Wisconsin-Madison School of Medicine and Public Health, agrees. He tells Newsweek that only around 4 percent of the variation in anxious temperament is a result of the brain connectivity described in the study. Connectivity is “not the whole story,” he says. “We need to keep studying this model to get the full picture of the complex neural and genetic mechanisms that underlie anxiety and anxiety disorders.”