By Gwendolyn Schanker, Journalism and Biology, 2018

Our brains are continually developing – led by a combination of neurological changes and environmental factors – well into adolescence. According to Heather Brenhouse, assistant professor of psychology at Northeastern, there’s a lot of mystery surrounding why the brain evolves the way it does and what factors cause changes in development.

“A lot of times things that happen early on in life, like chronic stress or infection, can actually lead to later vulnerability to depression, anxiety or addiction,” Brenhouse said.

That vulnerability is the subject of Brenhouse’s current research. Recently, her lab was awarded a five-year grant from the National Institutes of Health to study how key developmental connections in the brain are affected by early life stress.

More specifically, they’re examining how the prefrontal cortex (PFC) – the part of our brain involved in decision-making – connects to the brain’s limbic areas, like the amygdala, which process our emotions and stimulate responses like fear or anxiety.

“That connection is what gives us the ability to deal with our emotions in situation-appropriate ways,” Brenhouse said. “If the connection develops differently [than normal], then emotional processing can be altered, which can lead to illness.”

Brenhouse and her team are using animal models to understand this critical connection. They’re following up on data that was previously collected by other researchers in human children who spent their first few years in understaffed orphanages, whose connectivity was different than children who did not experience the same stress.

The lab has an ongoing collaboration with Northeastern psychology professor Craig Ferris, whose magnetic resonance imaging (MRI) technology can be used to understand brain structure.

“We’re tracing the connections with functional MRI as well as with a physical dye,” Brenhouse explained. This will not only help them better understand how the brain develops, but also how findings in humans translate to animals.

“Generally, they map on really well,” she said.

Prof. Heather Brenhouse

Eventually, these findings could be used to help develop strategies for dealing with mental illness before the fact – by addressing early stressful events rather than later symptoms.

“There are treatments available for mental illnesses like depression or anxiety disorders, but it’s been a hit-or-miss struggle to treat symptoms once they start,” Brenhouse said. “It will be much more effective if we can identify people that need help earlier.”

Understanding how brain circuitry affects behavior could potentially make a big difference in helping young children essentially “rewire their brains.”

“We’re going to start to know where to look and what kinds of strategies we need,” Brenhouse said, citing changes to diet or environment as examples of non-invasive interventions.

Brenhouse and her colleagues also plan to investigate how the brain interacts with other anatomical systems, like the immune system.

“When we’re stressed, we get sick more easily,” she said. “We’re interested in how those kinds of interactions develop, especially over adolescence, which is a particularly tumultuous time.”

They’re also studying how the timeline of development differs between the sexes.

“The trajectory of brain development is different between males and females, and may be differentially affected by early life stress,” she said. “More and more information is coming forward about all the differences that exist,” which may impact how males and females are treated for mental illness.

The research is an important step in helping the millions of people who could suffer from depression, anxiety, or other similar challenges.

“Being able to identify people who might need help before a lifetime of illness takes hold, who might now be falling through the cracks – it’s a very exciting idea,” she said.