The Sleep in Caenorhabditis elegans: What We Know Until Now

Abstract

Sleep, as one of the most important requirements of our brain, has a mystical nature. Despite long-standing studies, the molecular mechanisms and physiological properties of sleep have not been defined well as the complexity of the mammals' brain make it difficult to investigate the mechanisms and properties of sleep. Although some features of sleep have changed during evolution, its existence in such a simple animal, Caenorhabditis elegans, not only signifies the importance of sleep in even simple animals, but also allows the scientist to assess the core mechanism and biological events in an uncomplicated organism. This article reviews the information which exists about the characteristics of sleep in C. elegans, its circadian rhythm, the neurons and neurotransmitters responsible for each state, and the signaling molecules involved. Although much still remains to be resolved about the sleep of C. elegans, the available knowledge helps the scientists to recognize the properties better of this mysterious function of the brain.

Caenorhabditis elegans as a Promising Model Organism in Chronobiology

“…Summary of the basic circadian properties studied in C. elegans by different research groups. (Moosavi and Hatam, 2018;. The nematodes greatly reduce the release of PDF-1 during DTS suggesting that PDF signaling promotes arousal in C. elegans, as they do in Drosophila (Renn et al, 1999).…”

“…Unlike the circadian sleep in Drosophila and mammals, DTS occurs with an ultradian periodicity (it occurs four times during development, with a period of 8-10 h depending on the cultivation temperature) (Mata-Cabana et al, 2022) and is linked to the molting cycle rather than the 24 h light/dark cycle. Despite this difference, many molecular pathways regulating sleep in mammals and flies also regulate sleep in C. elegans , such as the PDF, PKA/cAMP, EGFR, dopamine, and PKG signaling pathways (Moosavi and Hatam, 2018; Trojanowski and Raizen, 2016). The nematodes greatly reduce the release of PDF-1 during DTS suggesting that PDF signaling promotes arousal in C. elegans , as they do in Drosophila (Renn et al, 1999).…”

“…On the other hand, EGF signaling promotes sleep and PKG activity is associated with sleep or sleep intensity. The overexpression of the EGF homolog LIN-3 causes cessation of feeding and locomotion in C. elegans (Moosavi and Hatam, 2018). EGF signaling appears primarily necessary for SIS, rather than DTS.…”

Four novel sleep-promoting peptides screened and identified from bovine casein hydrolysates using a patch-clamp model in vitro and Caenorhabditis elegans in vivo

“…26 The neurotransmitters dopamine, 5-hydroxytryptamine, and glutamic acid serve the function of regulating sleep balance in both mammals and C. elegans. 27 These characteristics provide great advantages to using C. elegans for the evaluation of sleep-promoting activity and the mechanism of compounds. 15 In this research, the sleep-promoting activity of CH was investigated using mice model.…”