STRESS ATTENUATES THE EXCITABILITY OF ACCUMBAL NEURONS PROJECTING TO THE LATERAL HYPOTHALAMUS: POTENTIAL CONSEQUENCES FOR BINGE EATING

Feeding can be largely perturbed by external experiences, like stress which reshapes food choices to diets that are high in sugar and fat, independent of metabolic needs. The neurobiology underlying this effect is not clear. Nucleus accumbens (NAc) projections to the lateral hypothalamus (LHA) have been shown to authorize feeding when inhibited, but whether stress causes plasticity in this pathway that affects feeding remains elusive. We hypothesized that, in mice, a stressor causing food overconsumption would reduce excitability in the NAc-LHA pathway. We observed, using ex vivo patch-clamp electrophysiology, that stress downregulates the excitability of the NAc-LHA pathway. We also observed that stress enhanced GABAB receptor signaling onto these neurons, as a possible expression mechanism. We also demonstrated that, despite stress-driven changes in this pathway, it retained its ability to strongly suppress palatable food intake upon in vivo optogenetic stimulation. Overall, our data reveal an important role for stress-induced plasticity in the NAc-LHA pathway, which might underlie uncontrollable overeating after experiencing stress.