The vagus nerve represents a complex neural relay allowing reciprocal transfer of information between peripheral organs and discrete brain regions. It has recently been pointed to serve as a critical regulator of nigrostriatal DA neurons. However, the cellular and functional underpinnings of this circuit (vagus→brainstem→DA), its extension to the mesolimbic DA system in reward-related dysfunctions (eating disorders) and the causal maladaptive alterations of the gut→DA axis remain largely unknown. We will tackle these point tacking advantage of in vivo integrative approaches in physiological and pathological (obesity) conditions.

The paraventricular thalamus (PVT) is a highly interconnected brain region which represents a functional hub to relay diverse information. Recently, it has been demostrate that PVT neurons are sensitive to dopamine. Whether and how dopaminoceptive PVT neurons control homeostatic and reward processes associated to food-related behaviors remain elusive. By using cell type-specific approches and in vivo technologies (chemogenetics, fiber photometry), we will shed light on these unsolved questions.

Nutritional (triglycerides, TG) and endogenous bioactive lipids (endocannabinoids) tightly regulate the activity and functions of the reward system. We have recently demonstrated that circulating TG gate the activity of dopaminoceptive striatal neurons. We now wish to understand whether and how lipids-dependent neuronal functions (mal)adapt depending on metabolic states. Using multi-scale approaches (from synapses to behaviors) we will unravel new forms of communications.