A new study by University of Iowa researchers sheds light on the link between stress and our brain. The authors uncovered a neural circuit connecting two distinct regions in the brain that control our body’s reaction to stress.
As part of the study, researchers analyzed how rats responded to various stress stimuli. The rats produced a passive or active reaction which was traced to a specific brain pathway.
In subsequent tests, the rats’ neural circuits were successfully manipulated, allowing them to override threats that would have typically frozen them in fear.
The study’s findings will help researchers better understand the relationships between stress and physical and mental health. One of the authors, Jason Radley, is an associate professor in the Department of Psychological and Brain Sciences.
Radley explained, “A lot of chronic stress diseases like depression and anxiety disorders are associated with what we call a passive coping behavior.”
He added, “We know that a lot of these conditions are caused by life stress. The simplest reason we’re interested in this pathway is thinking about it as a circuit that can promote resilience against stress.”
Studies have previously identified the pathway in the brain responsible for the body’s reaction to stress, but until now, it was not confirmed.
The rats involved in the study reacted in two distinct ways. When researchers inactivated the rat’s stress neural circuit, they were fearful, motionless, and passive.
Alternatively, researchers could prompt the rats to produce a more active and aggressive response to the same stimulus when the pathway was activated.
A third test conducted in the study revealed insight into chronic stress and why some people carry chronic stress longer than others. Researchers have begun to glean details as to why some people experience more “stress resilience,” though the exact mechanisms remain a mystery.
Radley believes, “It’s possible we can co-opt some of these brain circuits if we could understand the processes in the brain that can regulate resilience.” It is a hypothesis the authors intend to research further.