Starvation-induced sleep suppression requires the Drosophila brain nutrient sensor

Animals increase their locomotion activity and reduce sleep duration under starved conditions. This suggests that sleep and metabolic status are closely interconnected. The nutrient and hunger sensors in the Drosophila brain, including diuretic hormone 44 (DH44)-, CN-, and cupcake-expressing neurons, detect circulating glucose levels in the internal milieu, regulate the insulin and glucagon secretion and promote food consumption. Food deprivation is known to reduce sleep duration, but a potential role mediated by the nutrient and hunger sensors in regulating sleep and locomotion activity remains unclear. Here, we show that DH44 neurons are involved in regulating starvation-induced sleep suppression, but CN neurons or cupcake neurons may not be involved in regulating starvation-induced sleep suppression or baseline sleep patterns. Inactivation of DH44 neurons resulted in normal daily sleep durations and patterns under fed conditions, whereas it ablated sleep reduction under starved conditions. Inactivation of CN neurons or cupcake neurons, which were proposed to be nutrient and hunger sensors in the fly brain, did not affect sleep patterns under both fed and starved conditions. We propose that the glucose-sensing DH44 neurons play an important role in mediating starvation-induced sleep reduction.

Automated summary

Animals increase locomotion and decrease sleep when starved, indicating a close connection between sleep and metabolic status. The Drosophila brain has nutrient and hunger sensors, such as DH44-, CN-, and cupcake-expressing neurons, which detect glucose levels in the body and regulate insulin and glucagon secretion. In this study, DH44 neurons were found to be involved in regulating starvation-induced sleep suppression, while CN or cupcake neurons did not affect sleep patterns under both fed and starved conditions. Glucose-sensing DH44 neurons play an important role in mediating starvation-induced sleep reduction.