Fig. 5: Circuit-wide changes associated with sgACC/25 over-activation revealed with ¹⁸F-FDG PET imaging.

a Four marmosets had a subcutaneous port implanted into the jugular vein and were trained on a lengthened version of the aversive Pavlovian discriminative conditioning test in preparation for scanning. Saline (control) and DHK (over-activation) scans were counterbalanced. On the day of the scan (inset), animals were infused with saline or DHK and immediately injected with ¹⁸F-FDG ligand through the port. The conditioning session lasted 30 min to increase sensitivity of the ligand to perturbations in brain activity caused by the paradigm. On the day of scans, this consisted of four CS+/US+ pairings, two CS−/US− pairings and two “probe” trials of a CS+ alone to limit aversive US exposures. These were presented in a fixed order indicated on the timeline. b Contrast images calculated from standardized uptake value ratio (SUVR) maps of over-activation—control scans, showing brain regions with increased activity following over-activation. These included sgACC/25, the amygdala, the ventromedial (VMH) and lateral (LH) hypothalamic nuclei and temporal association area TH (p < 0.005, uncorrected). c Contrast images calculated from SUVR maps of control—over-activation scans, showing brain regions with reduced activity following over-activation. These included frontopolar cortex/9, dorsolateral prefrontal cortex (dlPFC)/46, central orbitofrontal cortex (OFC)/13 and the lateral caudate (p < 0.005, uncorrected). Source data are available from the corresponding author upon request.