How childhood maltreatment changes the brain

Childhood maltreatment may leave behind more than just bad memories. It could rewire how the brain responds to perceived threats.

A team of researchers led by Dr. Floris Klumpers of Radboud University in the Netherlands studying the way that the human brain reacts to perceived threats discovered the difference between the brains of people who were maltreated as children and those with healthy childhoods.

The researchers were studying two different samples of adults and how they reacted to the proximity of a threat using neuroimaging. Neural activity tied to defensive responses shifts between two different areas of the brain – the amygdala and an area called the bed nucleus of the stria terminalis – when the subject reacts to a threat, the researchers found.

Both regions are activated in response to a threat, though how the brain organizes which area responds to which threat is still unclear.

However, one of the samples showed unexpected activity: the balance of activity between the two defensive regions of the brain was different. Klumpers’ team found that the difference appeared to be tied to emotional abuse the subjects experienced during their childhood.

The researchers used harmless electric shocks to study activity in the two brain regions. In most of the participants, they found that anticipation of the shock increased activity in the bed nucleus of the stria terminalis. The shock itself increased activity in the amygdala.

The team of neuroscientists believes that the BNST regulates more distant threats and appears to be connected to areas of the brain that decide how to deal with them. The amygdala seems to be more connected to involuntary reactions such as a faster heartbeat and other fight or flight reactions, they said.

In participants who reported childhood maltreatment, though, the anticipation bypassed the BNST and triggered activity in the amygdala.

The discovery could offer insights into how negative stress in early life and childhood maltreatment affects people into adulthood.

The study has been published in the Journal for Neuroscience.

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By Kyla Cathey, Earth.com staff writer