AUTHOR=Tomita Jun , Ban Gosuke , Kato Yoshiaki S. , Kume Kazuhiko 

TITLE=Protocerebral Bridge Neurons That Regulate Sleep in Drosophila melanogaster

JOURNAL=Frontiers in Neuroscience

VOLUME=15

YEAR=2021

URL=https://www.frontiersin.org/journals/neuroscience/articles/10.3389/fnins.2021.647117

DOI=10.3389/fnins.2021.647117

ISSN=1662-453X

ABSTRACT=<p>The central complex is one of the major brain regions that control sleep in <italic>Drosophila</italic>. However, the circuitry details of sleep regulation have not been elucidated yet. Here, we show a novel sleep-regulating neuronal circuit in the protocerebral bridge (PB) of the central complex. Activation of the PB interneurons labeled by the <italic>R59E08-Gal4</italic> and the PB columnar neurons with <italic>R52B10</italic>-<italic>Gal4</italic> promoted sleep and wakefulness, respectively. A targeted GFP reconstitution across synaptic partners (t-GRASP) analysis demonstrated synaptic contact between these two groups of sleep-regulating PB neurons. Furthermore, we found that activation of a pair of dopaminergic (DA) neurons projecting to the PB (T1 DA neurons) decreased sleep. The wake-promoting T1 DA neurons and the sleep-promoting PB interneurons formed close associations. <italic>Dopamine 2-like receptor</italic> (<italic>Dop2R</italic>) knockdown in the sleep-promoting PB interneurons increased sleep. These results indicated that the neuronal circuit in the PB, regulated by dopamine signaling, mediates sleep-wakefulness.</p>