A nutrient-specific gut hormone arbitrates between courtship and feeding

Area of Science:

• Neuroscience
• Animal Behavior
• Endocrinology

Background:

• Animals must dynamically switch between behaviors like feeding and courtship based on internal states and external cues.
• Understanding the molecular and neuronal basis of these behavioral transitions is crucial for comprehending decision-making processes.

Purpose of the Study:

• To investigate the molecular and neuronal mechanisms underlying the switch from feeding to courtship behavior in Drosophila melanogaster.
• To identify the role of gut-derived signals in modulating these behavioral priorities.

Main Methods:

• Utilized Drosophila melanogaster as a model organism.
• Employed calcium imaging to study neuronal activity kinetics.
• Performed three-photon functional imaging in intact flies.
• Used optogenetics to stimulate specific cell populations.

Main Results:

• Starved male flies prioritize feeding over courtship, but consuming protein-rich food quickly reverses this preference.
• A nutrient-specific gut hormone, Diuretic hormone 31 (Dh31), is released upon ingestion of protein-rich food.
• Dh31 rapidly excites specific brain neurons expressing its receptor (Dh31R) via circulation.
• Two distinct populations of Dh31R+ neurons modulate feeding (via allatostatin-C) and courtship (via corazonin).

Conclusions:

• Gut-derived Dh31 acts as a key signal mediating the rapid switch from feeding to courtship behavior after protein consumption.
• This hormonal signaling involves distinct neuronal pathways in the brain that differentially regulate feeding and courtship.
• The study reveals a conserved mechanism linking nutrient intake to behavioral prioritization through gut-brain communication.