Differential regulation of the sleep homeostat by circadian and arousal inputs

TitleDifferential regulation of the sleep homeostat by circadian and arousal inputs
Publication TypeJournal Article
Year of Publication2019
AuthorsNi JD, Gurav AS, Liu W, Ogunmowo TH, Hackbart H, Elsheikh A, Verdegaal AA, Montell C
JournalElife
Volume8:e40487
Date Published2019 Feb 05
ISSN2050-084X
Abstract

One output arm of the sleep homeostat in appears to be a group of neurons with projections to the dorsal fan-shaped body (dFB neurons) of the central complex in the brain. However, neurons that regulate the sleep homeostat remain poorly understood. Using neurogenetic approaches combined with Ca imaging, we characterized synaptic connections between dFB neurons and distinct sets of upstream sleep-regulatory neurons. One group of the sleep-promoting upstream neurons is a set of circadian pacemaker neurons that activates dFB neurons via direct glutaminergic excitatory synaptic connections. Opposing this population, a group of arousal-promoting neurons downregulates dFB axonal output with dopamine. Co-activating these two inputs leads to frequent shifts between sleep and wake states. We also show that dFB neurons release the neurotransmitter GABA and inhibit octopaminergic arousal neurons. We propose that dFB neurons integrate synaptic inputs from distinct sets of upstream sleep-promoting circadian clock neurons, and arousal neurons.

DOI10.7554/eLife.40487
Alternate JournalElife
PubMed ID30719975
PubMed Central IDPMC6363385
Grant ListDC007864 / / National Institute on Deafness and Other Communication Disorders /
EY008117 / / National Eye Institute /