Despite recent advances in the understanding of molecular events associated with energy homeostasis, higher-order brain centres responsible for eliciting and/or modulating food intake are not yet fully identified. This project has sought to discover brain areas that project toward peripheral organs involved in the food intake process (e.g. salivary glands, taste papillae, orofacial/lingual muscles, etc.) and to characterize the neurochemical properties of neurons in those brain regions. To achieve our objective we have identified neurons belonging to multiple neuronal circuits mapped by means of recombinant pseudorabies viruses (PRVs), a retrograde tracing agent, encoding various reporter proteins such as beta-galactosidase, green fluorescent protein (GFP) or red fluorescent protein (RFP). PRV strains were injected in the following peripheral organs of male CB57BL/6J mice that had previously received an IP dose of ketamine/xylazine (60 mg/kg and 7 mg/kg, respectively): submandibular salivary gland, masseter muscle, and circumvallate taste papilla; in some cases we injected two different PRV strains in two different organs (n=3 or 4 for each group). Brains from infected mice were analysed by immunofluorescence microscopy. Brain areas identified by this approach, and belonging to multiple neuronal circuits, were defined as putative food intake control centers (FICCs). Our results indicate that discrete amygdaloid nuclei as well as some cortical structures (insular and rhinal cortices) are candidates to be FICCs. A further characterization of neuronal subtypes in FICCs is being performed by identification of PRV-infected neurons in transgenic mice lines expressing GFP in different subtypes of neurons, including those expressing the neuropeptide Y (NPY) and proopio-melanocortin (POMC). Identification of good markers of FICC neurons and/or candidate genes to be involved in food intake regulation, will provide the basis to design ad hoc loss and gain of function studies aimed to probe the role of those candidate neurons and/or genes in determining the molecular and physiological mechanisms involved in the food intake process and the behavioral imbalances associated with eating disorders and ailments with high impact in our society, such as anorexia and obesity.