Coordinated excitatory and inhibitory circuits governing unpredictable threat induced anxiety

Anxiety is elicited by excessive apprehension about unpredictable threats. However, the neural circuit governing unpredictable threat induced anxiety remains unclear. Here, we found ventral bed nucleus of the stria terminalis (vBNST) GABAergic neurons displayed selective activation to unpredictable threats by means ofthrough coordinated excitatory input from insular cortex (IC) glutamergic neurons and inhibitory input from lateral nucleus of the amygdala (CeL) somatostatin (SOM) neurons. Using activity-dependent neuronal tagging technology, we found that unpredictable threat responsive cells in vBNST drive freezing and anxiety via projections to ventral lateral periaqueductal grey (vlPAG) and median nucleus of the amygdala (CeM) respectively. Finally, we identified KCNQ3 plays an essential role in hyperactivity of vBNST GABAergic neurons and induced anxiety. These data identified a forward inhibitory circuit that determine the selective activation of vBNST in unpredictable threat and anxiety, and suggest that Kcnq3 KCNQ3 channel acts as a promising target in treatment of anxiety disorder following unpredictable stress. Overall design: The molecular mechanism underlying the altered activity of vBNST CS- responsive ensemble to unpredictable threats is still unknown. We thus employed phosphorylated translating ribosome affinity purification (pTRAP) combining with RNA sequencing to screen the key molecules involved in vBNST's response to unpredictable threats (Knight et al., 2012; Zhang et al., 2022). vBNST were prepared from mice 90 min after CS+ or CS- test and the precipitated ribosomal RNA was sequenced following immunoprecipitated (IP) with a phosphoS6 (Ser244, Ser247)-specific antibody