Satiation State-dependent Dopaminergic Control of Food Seeking in Drosophila

Hunger evokes stereotypic behaviors that favor the discovery of nutrients. The neural pathways that coordinate internal and external cues to motivate food seeking behaviors are only partly known. Drosophila that are food deprived increase locomotor activity, are more efficient in locating a discrete source of nutrition, and are willing to overcome adversity to obtain food. Here we developed a semi-naturalistic assay and show that two distinct dopaminergic neural circuits regulate food-seeking behaviors. One group, the PAM neurons, functions in food deprived flies while the other functions in well fed flies, and both promote food seeking. These satiation state-dependent circuits converge on dopamine D1 receptor-expressing Kenyon cells of the mushroom body, where neural activity promotes food seeking behavior independent of satiation state. These findings provide evidence for active food seeking in well-fed flies that is separable from hunger-driven seeking.