Bed nucleus of the stria terminalis connectivity during food cue and taste processing under stress.

Abstract

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 under stress modulate BNST effective connectivity. Forty-eight participants were presented a palatable and neutral beverage cue before receiving the corresponding beverages under low- and high-stress conditions. Beverage cues under stress downregulated BNST effective connectivity to the nucleus accumbens, orbitofrontal cortex, and dorsal mid-insula (dmINS), with the strength of cue-related downregulation of BNST-to-orbitofrontal effective connectivity related to changes in participants' subjective stress. In addition, taste receipt under stress downregulated effective connectivity from the dmINS to BNST. These findings provide evidence that stress-related food cue and taste processing modulates BNST reward circuitry, offering a mechanistic perspective on how stress alters responsivity to food cues.