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Published October 9, 2017 | Supplemental Material + Accepted Version
Journal Article Open

The Jellyfish Cassiopea Exhibits a Sleep-like State


Do all animals sleep? Sleep has been observed in many vertebrates, and there is a growing body of evidence for sleep-like states in arthropods and nematodes. Here we show that sleep is also present in Cnidaria, an earlier-branching metazoan lineage. Cnidaria and Ctenophora are the first metazoan phyla to evolve tissue-level organization and differentiated cell types, such as neurons and muscle. In Cnidaria, neurons are organized into a non-centralized radially symmetric nerve net that nevertheless shares fundamental properties with the vertebrate nervous system: action potentials, synaptic transmission, neuropeptides, and neurotransmitters . It was reported that cnidarian soft corals and box jellyfish exhibit periods of quiescence, a pre-requisite for sleep-like states, prompting us to ask whether sleep is present in Cnidaria. Within Cnidaria, the upside-down jellyfish Cassiopea spp. displays a quantifiable pulsing behavior, allowing us to perform long-term behavioral tracking. Monitoring of Cassiopea pulsing activity for consecutive days and nights revealed behavioral quiescence at night that is rapidly reversible, as well as a delayed response to stimulation in the quiescent state. When deprived of nighttime quiescence, Cassiopea exhibited decreased activity and reduced responsiveness to a sensory stimulus during the subsequent day, consistent with homeostatic regulation of the quiescent state. Together, these results indicate that Cassiopea has a sleep-like state, supporting the hypothesis that sleep arose early in the metazoan lineage, prior to the emergence of a centralized nervous system.

Additional Information

© 2017 Elsevier. Received 30 April 2017, Revised 17 July 2017, Accepted 4 August 2017, Available online 21 September 2017. Published: September 21, 2017. We thank Chris Blair from the National Aquarium, MD; Monica Medina and Aki Ohdera from Pennsylvania State University, PA; and Wyatt Patry from the Monterey Bay Aquarium, CA, for generously supplying Cassiopea medusa and polyps and Dr. John Bedbrook for critical reading of the manuscript. We thank Kiersten Darrow and Michael Schaadt of the Cabrillo Marine Aquarium, CA, for input on husbandry. We thank http://dryades.units.it/jelly for an image of Cassiopea (CC 3.01 NC-BY-SA) that was adapted in Figure 3 and Figure S1. This work was supported by the NIH Director's New Innovator Award/PECASE (IDP20D017782-01; to V.G.), the James S. McDonnell Foundation for Complex Systems Science (220020365; to L.G.), the NIMH under a Ruth L. Kirschstein National Research Service Award (F31MH102913; to C.N.B.), the NINDS under a Ruth L. Kirschstein National Research Service Award (F31NS100519; to R.D.N.), a National Science Foundation Graduate Research Fellowship (1144469; to M.J.A.), and an NIH training grant (T32GM007616; to C.N.B. and R.D.N.). V.G. is a Heritage Principal Investigator supported by the Heritage Medical Research Institute; P.W.S. is an investigator with the HHMI (047-101), which supported this research. Data and Software Availability: Code used for tracking jellyfish activity and analysis is available at https://github.com/GradinaruLab/Jellyfish. Author Contributions: R.D.N., C.N.B., and M.J.A. conceived the project. V.G., P.W.S., and L.G. oversaw the project. R.D.N., C.N.B., and M.J.A. performed experiments and data analysis. R.D.N., C.N.B., M.J.A., and T.B. conceptualized, designed, and built experimental setups. C.N.B. and R.D.N. wrote image-processing and data-analysis scripts with J.S.B.'s oversight. D.A.P. provided input on experimental design. R.D.N., C.N.B., and M.J.A. wrote the paper with input from J.S.B., D.A.P., V.G., P.W.S., and L.G.

Attached Files

Accepted Version - nihms907190.pdf

Supplemental Material - mmc1.pdf

Supplemental Material - mmc2.mp4

Supplemental Material - mmc3.mp4

Supplemental Material - mmc4.zip


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Additional details

August 21, 2023
October 17, 2023