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Sleep is a fundamental feature of life for virtually all multicellular animals, but many questions remain about how sleep is regulated by circadian rhythms, homeostatic sleep drive that builds up with wakefulness, and modifying factors such as hunger or social interactions, as well as about the biological functions of sleep. Substantial headway has been made in the study of both circadian rhythms and sleep in the fruit flyDrosophila melanogaster, much of it through studies of individual fly activity usingDrosophilaactivity monitors (DAMs). Here, we describe approaches for the activation of specific neurons of interest using optogenetics (involving genetic modifications that allow for light-based neuronal activation) and thermogenetics (involving genetic modifications that allow for temperature-based neuronal activation) so that researchers can evaluate the roles of those neurons in controlling rest and activity behavior. In this protocol, we describe how to set up a rig for simultaneous optogenetic or thermogenetic stimulation and activity monitoring for analysis of sleep and circadian rhythms inDrosophila, how to raise appropriate flies, and how to perform the experiment. This protocol will allow researchers to assess the causative role in the regulation of sleep and activity rhythms of any genetically tractable subset of cells.
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This content will become publicly available on December 1, 2026
The DrosophilaSIFamide Receptor Regulates Sleep and Feeding in a Time‐Of‐Day Specific Manner
ABSTRACT To optimize health, organisms must coordinate energy intake and expenditure and apportion related behaviors to appropriate times of day. In the fruit fly,Drosophila melanogaster, the SIFamide (SIFa) neuropeptide impacts multiple behavioral outputs important for energy regulation, including reproductive activity, sleep, and feeding. SIFa‐expressing neurons receive convergent inputs from circadian and homeostatic brain regions and extend elaborate projections throughout the central nervous system. Consistent with this distribution pattern, the SIFa receptor (SIFaR) is widely expressed in the brain and ventral nerve cord, providing the anatomical substrate for SIFa signaling to influence a broad range of neuronal functions. To further explore the pleiotropic role of SIFa signaling in behavioral control, we have assessed survival, locomotor activity, sleep, and feeding inSIFaRmutant flies, as well as in flies with RNA interference‐induced reduction ofSIFaRexpression. We find that loss of SIFaR has a complex effect on fly survival that is background‐ and allele‐specific. However, outcrossedSIFaRmutant flies are viable, enabling monitoring of adult behavior. These flies exhibit elevated locomotor activity, reduced sleep, and increased feeding at specific times of day. We also find thatSIFaRmutations drastically decrease starvation resistance. These results suggest a prominent role for SIFaR in integrating homeostatic and circadian information to coordinate the magnitude and timing of energy balance‐related behaviors.
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- Award ID(s):
- 1942167
- PAR ID:
- 10677505
- Publisher / Repository:
- John Wiley & Sons Ltd and International Behavioural and Neural Genetics Society
- Date Published:
- Journal Name:
- Genes, Brain and Behavior
- Volume:
- 24
- Issue:
- 6
- ISSN:
- 1601-1848
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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