Chapter 11 - Monitoring Sleep and Arousal in Zebrafish
Introduction
Sleep is essential, time consuming, and conserved across the animal kingdom, yet it remains one of the major mysteries of biology. What is the function of sleep, and how is it regulated by genes and neurons? Since the discovery of characteristic electroencephalographic (EEG) signatures for states of sleep and waking in the late 1930s (Davis et al., 1937), mammalian model systems have dominated sleep research. However, behavioral observations over the past decade have demonstrated that non-mammalian systems, including Drosophila (Hendricks et al., 2000, Shaw et al., 2000), Caenorhabditis elegans (Raizen et al., 2008, Van Buskirk and Sternberg, 2007), and zebrafish (Prober et al., 2006, Yokogawa et al., 2007, Zhdanova et al., 2001), have sleep-like states. These “simple” model systems allow researchers to bring large-scale genetics and in vivo imaging to bear on fundamental questions of sleep biology. Zebrafish is an attractive model because it combines the facile genetics of invertebrates with brains that are morphologically and molecularly analogous to mammals. In this chapter, we review the progress of sleep studies in zebrafish and discuss the high-throughput methods (Fig. 1) we have developed to study larval zebrafish sleep/wake behaviors.
Section snippets
Behavior
Sleep is a period of reversible, inattentive behavioral quiescence that can be distinguished from quiet wakefulness using several behavioral criteria (Borbely and Tobler, 1996, Campbell and Tobler, 1984, Cirelli, 2009). Sleep-like rest periods are typically associated with a species-specific posture and location, and are regulated in a circadian (about 24 h) manner (Borbely and Tobler, 1996). Importantly, sleep is associated with an increased arousal threshold in response to stimuli, although
Methodological Considerations—from Drosophila to Danio
Two major methods have been used to track locomotor behavior of animals, either by counting the number of times an animal breaks an infrared beam or by direct analysis of movements captured by video. Pioneering work on circadian rhythms (Konopka and Benzer, 1971) and sleep (Hendricks et al., 2000, Shaw et al., 2000) in Drosophila predominantly used the infrared beam break method, which measures when the fly crosses an infrared beam in the center of a tube. Some work on zebrafish (Hurd et al.,
Conclusion
Only a decade old, the study of sleep in non-mammalian systems is still in its infancy. While early zebrafish sleep studies have focused on establishing the existence of behavioral sleep regulated by conserved mechanisms, the challenge ahead is to use the zebrafish sleep model to uncover heretofore unsuspected aspects of the neuronal and genetic control of sleep/wake regulation. Recent studies that potentially link Hcrt signaling to pineal gland regulation (Appelbaum et al., 2009) and that
References (56)
- et al.
Melatonin reduces locomotor activity and circulating cortisol in goldfish
Horm. Behav.
(2010) - et al.
Sleep regulation: Relation to photoperiod, sleep duration, waking activity, and torpor
Prog. Brain Res.
(1996) - et al.
Animal sleep: A review of sleep duration across phylogeny
Neurosci. Biobehav. Rev.
(1984) - et al.
Narcolepsy in orexin knockout mice: Molecular genetics of sleep regulation
Cell
(1999) - et al.
Regulation of hypocretin (orexin) expression in embryonic zebrafish
J. Biol. Chem.
(2006) - et al.
Genetic ablation of orexin neurons in mice results in narcolepsy, hypophagia, and obesity
Neuron
(2001) - et al.
Rest in Drosophila is a sleep-like state
Neuron
(2000) - et al.
Circadian rhythms of locomotor activity in zebrafish
Physiol. Behav.
(1998) - et al.
Circadian rhythms of locomotor activity in the goldfish Carassius auratus
Physiol. Behav.
(1996) - et al.
A computer image processing system for quantification of zebrafish behavior
J. Neurosci. Methods
(2004)
The sleep disorder canine narcolepsy is caused by a mutation in the hypocretin (orexin) receptor 2 gene
Cell
Behavioral correlates of activity in identified hypocretin/orexin neurons
Neuron
Reduced number of hypocretin neurons in human narcolepsy
Neuron
Feeding entrainment of locomotor activity rhythms, digestive enzymes and neuroendocrine factors in goldfish
Physiol. Behav.
Distinct narcolepsy syndromes in Orexin receptor-2 and Orexin null mice: Molecular genetic dissection of non-REM and REM sleep regulatory processes
Neuron
Melatonin promotes sleep-like state in zebrafish
Brain Res.
Sleep–wake regulation and hypocretin–melatonin interaction in zebrafish
Proc. Natl. Acad. Sci. U. S. A.
High-throughput ethomics in large groups of Drosophila
Nat. Methods
Modulation of locomotor activity in larval zebrafish during light adaptation
J. Exp. Biol.
Asynchronous oscillations of two zebrafish CLOCK partners reveal differential clock control and function
Proc. Natl. Acad. Sci. U. S. A.
The genetic and molecular regulation of sleep: From fruit flies to humans
Nat. Rev. Neurosci.
Changes in human brain potentials during the onset of sleep
Science
Autonomous onset of the circadian clock in the zebrafish embryo
EMBO J.
Zebrafish larvae lose vision at night
Proc. Natl. Acad. Sci. U. S. A.
OFF ganglion cells cannot drive the optokinetic reflex in zebrafish
Proc. Natl. Acad. Sci. U. S. A.
A behavioral assay to measure responsiveness of zebrafish to changes in light intensities
J. Vis. Exp
Automated visual tracking for studying the ontogeny of zebrafish swimming
J. Exp. Biol.
Waking experience affects sleep need in Drosophila
Science
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