Our response to a threat seem to depend on the balance of activity between two specific brain regions. This is suggested by neuroimaging data from two independent samples of adults in the Netherlands published in The Journal of Neuroscience on September 11. Researchers from Radboudumc and Radboud University provide the first proof that these two brain areas help to switch between responses to anticipated and real threats.The amygdala and a closely related region called the bed nucleus of the stria terminalis (BNST) are both activated in response to a threat but it is unclear how these regions orchestrate defensive responses in humans. Guillen Fernandez and colleagues from Radboud University and Radboudumc found that anticipation of an uncomfortable but painless electrical shock was associated with increased activity in BNST, which is strongly connected with other brain regions that may be involved in deciding how to respond to a threat. In contrast, the shock itself was associated with increased activity in the amygdala, which maintains stronger connections with lower brain regions that may facilitate immediate and involuntary responses to acute danger, such as increased heart rate.
Finally, the authors found that participants who reported greater childhood maltreatment - primarily emotional abuse and neglect rather than physical and sexual abuse - exhibited increased amygdala activity during shock anticipation. This finding shows how early life stress may impact an individual’s perception of distant threats.
PublicationHow human amygdala and bed nucleus of the stria terminalis may drive distinct defensive responses