title: Brain mechanisms and motivation.
mesh_terms: D000818:Animals; D001522:Behavior, Animal; D001921:Brain / Q000502:physiology*; D001931:Brain Mapping; D004327:Drinking Behavior; D004777:Environment; D005247:Feeding Behavior; D006706:Homeostasis; D008959:Models, Neurological; D008960:Models, Psychological; D009042:Motivation; D051381:Rats