Threat imminence reveals links among unfolding of anticipatory physiological response, cortical-subcortical intrinsic functional connectivity, and anxiety

Excessive expression of threat-anticipatory defensive responses is central in anxiety. Animal research indicates that anticipatory responses are dynamically organized by threat imminence and rely on conserved circuitry. Insight from translational work on threat imminence could guide mechanistic research mapping abnormal function in this circuitry to aberrant defensive responses in anxiety. Here, we initiate such research. Fifty pediatric anxiety patients and healthy-comparisons (33 females) completed a threat-anticipation task whereby cues signaled delivery of highly-painful (threat) or non-painful (safety) heat. Temporal changes in skin-conductance indexed defensive responding as function of threat imminence. Resting-state functional connectivity data were used to identify intrinsic-function correlates of anticipatory response within a specific functional network derived from translational research. Results indicate that anxiety was associated with greater increase in anticipatory response as threats became more imminent. Magnitude of increase in threat-anticipatory responses corresponded to intrinsic connectivity within a cortical-subcortical circuit; importantly, more severe anxiety was associated with greater connectivity between ventromedial prefrontal cortex and hippocampus and basolateral amygdala, a circuit implicated in animal models of anxiety. These findings link basic-translational and clinical research, highlighting aberrant intrinsic function in conserved defensive circuitry as potential pathophysiological mechanism in anxiety.