Insights into the Neurobiology of Behavioral Inhibition from Nonhuman Primate Models

Children with extreme behavioral inhibition (BI) are at a significantly greater risk to develop anxiety disorders later in life. We and others have identified similar early-life temperamental BI in nonhuman primates (NHPs), including rhesus monkeys. NHP models of BI provide a unique opportunity to study the neurobiology of BI in a species that shares biological, developmental, and socioemotional similarities with humans. Rhesus monkey models have identified a distributed brain circuit that includes the central extended amygdala (EAc) as being critical for the genesis of BI. By leveraging multimodal neuroimaging, brain lesions, RNA-sequencing, and viral vector manipulations in rhesus monkeys, these studies have identified specific brain regions, genetic factors, and molecular mechanisms that causally contribute to BI. Here, we discuss these findings from NHPs and how they fit into a translational framework that can contribute to our understanding of the neural circuits that give rise to the risk to develop anxiety and depressive disorders.