RESUMO
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 fly Drosophila melanogaster, much of it through studies of individual fly activity using Drosophila activity 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 in Drosophila, 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.
RESUMO
Sleep is a fundamental feature of life for virtually all multicellular animals, but many questions remain about how sleep is regulated and what biological functions it plays. Substantial headway has been made in the study of both circadian rhythms and sleep in the fruit fly Drosophila melanogaster, much of it through studies of individual fly activity using beam break counts from Drosophila activity monitors (DAMs). The number of laboratories worldwide studying sleep in Drosophila has grown from only a few 20 years ago to hundreds today. The utility of these studies is limited by the quality of the metrics that can be extracted from the data. Many software options exist to help analyze DAM data; however, these are often expensive or have significant limitations. Therefore, we describe here a method for analyzing DAM-based data using the sleep and circadian analysis MATLAB program (SCAMP). This user-friendly software has an advantage of combining several analyses of both sleep and circadian rhythms in one package and produces graphical outputs as well as spreadsheets of the outputs for further statistical analysis. The version of SCAMP described here is also the first published software package that can analyze data from multibeam DAM5Ms, enabling determination of positional preference over time.
RESUMO
Sleep is important for survival, and the need for sleep is conserved across species. In the past two decades, the fruit fly Drosophila melanogaster has emerged as a promising system in which to study the genetic, neural, and physiological bases of sleep. Through significant advances in our understanding of the regulation of sleep in flies, the field is poised to address several open questions about sleep, such as how the need for sleep is encoded, how molecular regulators of sleep are situated within brain networks, and what the functions of sleep are. Here, we describe key findings, open questions, and commonly used methods that have been used to inform existing theories and develop new ways of thinking about the function, regulation, and adaptability of sleep behavior.
