Stress modulates BNST connectivity during food cue and taste processing: a 7T dynamic causal modelling study

Across species, stress drives alterations in feeding behaviour, including heightened food-seeking and the overconsumption of palatable foods. The bed nucleus of the stria terminalis (BNST) acts as a neural hub linking stress and reward circuits. However, its role in human food cue and taste processing under stress remains unclear. Here, using 7-Tesla fMRI, dynamic causal modelling, and in-scanner taste delivery, we demonstrate that beverage cues and taste receipt modulate effective connectivity of the BNST under stress. Forty-eight participants were presented palatable and neutral beverage cues before receiving the corresponding beverages under low- and high-stress conditions. We found that beverage cue and taste receipt under stress inhibits BNST effective connectivity to the nucleus accumbens, orbitofrontal cortex, and anterior insula. Moreover, taste receipt under high stress has an inhibitory influence on connectivity from the anterior insula to the BNST, the strength of which predicts participant stress sensitivity. These findings provide the first evidence in humans that high-stress food cue and taste processing modulates BNST effective connectivity, leading to the inhibition of cortico-striatal circuitry. *Eva Guerrero-Hreins & Matthew D. Greaves are co-first authors. **Priya Sumithran, Robyn M Brown & Trevor Steward share co-senior authorship.