Coupled sensing of hunger and thirst signals coordinates food and water ingestion in Drosophila

Summary

Date: 
October 17, 2018 - 12:00pm - 1:00pm
Location: 
Northwest Building, Room 243
About the Speaker
Name: 
Nick Jourjine
Speaker Title: 
Postdoctoral Researcher
Speaker Affiliation: 
Hoekstra Lab

Food and water ingestion are innate behaviors essential for animal survival and human health.

Although molecular and neural mechanisms underlying these behaviors are currently being uncovered, less is known about how they interact to maintain internal homeostasis. We have recently used genetic, behavioral, and anatomical studies in Drosophila to identify a group of four genetically defined neurons that underlie such an interaction. Activation of these neurons is sufficient to concurrently promote sugar consumption and restrict water consumption, while inactivation promotes water consumption and restricts sugar consumption. By calcium imaging studies, we have also shown that these neurons are directly regulated by a peptide signal of hunger, adipokinetic hormone (the functional homolog of glucagon in insects), and by an internal signal of thirst, extracellular osmolality. Finally, we have identified a peptide receptor and an osmolality-sensitive ion channel that underlie this regulation. Thus, a small population of neurons senses internal signals of nutrient and water availability to balance sugar and water consumption in a manner that promotes homeostasis. Current work is aimed at identifying neural circuits downstream of these neurons and asking how they influence motor programs underlying food and water ingestion.