Sleep is essential component of life. Even though the research in this field develops constantly, there are still many aspects of this rather complex process that remains to be fully clarified. One of these aspects, reason why we actually sleep, is perhaps the most crucial. In this mini review we aim to address this question and discuss potential functions of sleep. Many recent scientific papers are currently available that covers similar topic. We tried to summarize these recent findings. There are certainly many ways how to approach this rather complex issue. Our article will specifically focus on role of sleep in neuronal development, synaptic plasticity, memory consolidation or mental health in general. Its role in immune system functioning will also be mentioned. Moreover, we will also consider more general functions of sleep, such as well-being of the organisms or securing survival of the individual. In conclusion, we will highlight possible main function of sleep.

National Institute of Mental Health Klecany Czech Republic

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ACHERMANN P, DIJK DJ, BRUNNER DP, BORBELY AA. A model of human sleep homeostasis based on EEG slow-wave activity: quantitative comparison of data and simulations. Brain Res Bull. 1993;31:97–113. doi: 10.1016/0361-9230(93)90016-5. PubMed DOI

ANDERSON AL, THOMASON ME. Functional plasticity before the cradle: a review of neural functional imaging in the human fetus. Neurosci Biobehav Rev. 2013;37:2220–2232. doi: 10.1016/j.neubiorev.2013.03.013. PubMed DOI

ANDERSON KN, BRADLEY AJ. Sleep disturbance in mental health problems and neurodegenerative disease. Nat Sci Sleep. 2013;5:61–75. doi: 10.2147/NSS.S34842. PubMed DOI PMC

AYAS NT, WHITE DP, MANSON JE, STAMPFER MJ, SPEIZER FE, MALHOTRA A, HU FB. A prospective study of sleep duration and coronary heart disease in women. Arch Intern Med. 2003;163:205–209. doi: 10.1001/archinte.163.2.205. PubMed DOI

BENINGTON JH, HELLER HC. Restoration of brain energy metabolism as the function of sleep. Prog Neurobiol. 1995;45:347–360. doi: 10.1016/0301-0082(94)00057-O. PubMed DOI

BESEDOVSKY L, LANGE T, BORN J. Sleep and immune function. Pflugers Arch. 2012;463:121–137. doi: 10.1007/s00424-011-1044-0. PubMed DOI PMC

BROWN RE, BASHEER R, McKENNA JT, STRECKER RE, McCARLEY RW. Control of sleep and wakefulness. Physiol Rev. 2012;92:1087–1187. doi: 10.1152/physrev.00032.2011. PubMed DOI PMC

CARLEY DW, FARABI SS. Physiology of Sleep. Diabetes Spectr. 2016;29:5–9. doi: 10.2337/diaspect.29.1.5. PubMed DOI PMC

CIRELLI C, SHAW PJ, RECHTSCHAFFEN A, TONONI G. No evidence of brain cell degeneration after long-term sleep deprivation in rats. Brain Res. 1999;840:184–193. doi: 10.1016/S0006-8993(99)01768-0. PubMed DOI

FICCA G, LOMBARDO P, ROSSI L, SALZARULO P. Morning recall of verbal material depends on prior sleep organization. Behav Brain Res. 2000;112:159–163. doi: 10.1016/S0166-4328(00)00177-7. PubMed DOI

FRANK MG, CANTERA R. Sleep, clocks, and synaptic plasticity. Trends Neurosci. 2014;37:491–501. doi: 10.1016/j.tins.2014.06.005. PubMed DOI PMC

GOTTLIEB DJ, PUNJABI NM, NEWMAN AB, RESNICK HE, REDLINE S, BALDWIN CM, NIETO FJ. Association of sleep time with diabetes mellitus and impaired glucose tolerance. Arch Intern Med. 2005;165:863–867. doi: 10.1001/archinte.165.8.863. PubMed DOI

GUZMAN-MARIN R, SUNTSOVA N, BASHIR T, NIENHUIS R, SZYMUSIAK R, McGINTY D. Rapid eye movement sleep deprivation contributes to reduction of neurogenesis in the hippocampal dentate gyrus of the adult rat. Sleep. 2008;31:167–175. doi: 10.1093/sleep/31.2.167. PubMed DOI PMC

HASLER G, BUYSSE DJ, KLAGHOFER R, GAMMA A, AJDACIC V, EICH D, ROSSLER W, ANGST J. The association between short sleep duration and obesity in young adults: a 13-year prospective study. Sleep. 2004;27:661–666. doi: 10.1093/sleep/27.4.661. PubMed DOI

IMERI L, OPP MR. How (and why) the immune system makes us sleep. Nat Rev Neurosci. 2009;10:199–210. doi: 10.1038/nrn2576. PubMed DOI PMC

JEWETT KA, TAISHI P, SENGUPTA P, ROY S, DAVIS CJ, KRUEGER JM. Tumor necrosis factor enhances the sleep-like state and electrical stimulation induces a wake-like state in co-cultures of neurons and glia. Eur J Neurosci. 2015;42:2078–2090. doi: 10.1111/ejn.12968. PubMed DOI PMC

JOUVET M. Paradoxical sleep as a programming system. J Sleep Res 7 Suppl. 1998;1:1–5. doi: 10.1046/j.1365-2869.7.s1.1.x. PubMed DOI

JUNG CM, MELANSON EL, FRYDENDALL EJ, PERREAULT L, ECKEL RH, WRIGHT KP. Energy expenditure during sleep, sleep deprivation and sleep following sleep deprivation in adult humans. J Physiol. 2011;589:235–244. doi: 10.1113/jphysiol.2010.197517. PubMed DOI PMC

KRUEGER JM, FRANK MG, WISOR JP, ROY S. Sleep function: Toward elucidating an enigma. Sleep Med Rev. 2016;28:46–54. doi: 10.1016/j.smrv.2015.08.005. PubMed DOI PMC

LANGE T, DIMITROV S, BOLLINGER T, DIEKELMANN S, BORN J. Sleep after vaccination boosts immunological memory. J Immunol. 2011;187:283–90. doi: 10.4049/jimmunol.1100015. PubMed DOI

LINDSTEDT SL, LASTAYO PC, REICH TE. When active muscles lengthen: properties and consequences of eccentric contractions. News Physiol Sci. 2001;16:256–261. doi: 10.1152/physiologyonline.2001.16.6.256. PubMed DOI

MACERA CA, ARALIS HJ, RAUH MJ, MacGREGOR AJ. Do sleep problems mediate the relationship between traumatic brain injury and development of mental health symptoms after deployment? Sleep. 2013;36:83–90. doi: 10.5665/sleep.2306. PubMed DOI PMC

MACKIEWICZ M, SHOCKLEY KR, ROMER MA, GALANTE RJ, ZIMMERMAN JE, NAIDOO N, BALDWIN DA, JENSEN ST, CHURCHILL GA, PACK AI. Macromolecule biosynthesis: a key function of sleep. Physiol Genomics. 2007;31:441–457. doi: 10.1152/physiolgenomics.00275.2006. PubMed DOI

MIGNOT E. Why we sleep: the temporal organization of recovery. PLOS Biology. 2008;6:0661–0669. doi: 10.1371/journal.pbio.0060106. PubMed DOI PMC

PEIGNEUX P, LEPROULT R. Theories on the Functions of Sleep. In: BASSETTI C, DOGAS Z, PEIGNEUX P, editors. Sleep Medicine Textbook. European Sleep Research Society (ESRS); Regensburg: 2014.

RÁCZ B, DUŠKOVÁ M, STÁRKA L, HAINER V, KUNEŠOVÁ M. Links between the circadian rhythm, obesity and the microbiome. Physiol Res. 2018;67:S409–S420. doi: 10.33549/physiolres.934020. PubMed DOI

RAMANATHAN L, GULYANI S, NIENHUIS R, SIEGEL JM. Sleep deprivation decreases superoxide dismutase activity in rat hippocampus and brainstem. Neuroreport. 2002;13:1387–1390. doi: 10.1097/00001756-200208070-00007. PubMed DOI PMC

RAMM P, FROST BJ. Cerebral and local cerebral metabolism in the cat during slow wave and REM sleep. Brain Res. 1986;365:112–124. doi: 10.1016/0006-8993(86)90728-6. PubMed DOI

REILLY T, WATERHOUSE J. Altered sleep-wake cycles and food intake: the Ramadan model. Physiol Behav. 2007;90:219–228. doi: 10.1016/j.physbeh.2006.09.004. PubMed DOI

RICKARD TC, CAI DJ, RIETH CA, JONES J, ARD MC. Sleep does not enhance motor sequence learning. J Exp Psychol Learn Mem Cogn. 2008;34:834–842. doi: 10.1037/0278-7393.34.4.834. PubMed DOI

ROFFWARG HP, MUZIO JN, DEMENT WC. Ontogenetic development of the human sleep-dream cycle. Science. 1966;152:604–619. doi: 10.1126/science.152.3722.604. PubMed DOI

SAVAGE VM, WEST GB. A quantitative, theoretical framework for understanding mammalian sleep. Proc Natl Acad Sci U S A. 2007;104:1051–1056. doi: 10.1073/pnas.0610080104. PubMed DOI PMC

SHETH BR, NGUYEN N, JANVELYAN D. Does sleep really influence face recognition memory? PLoS One. 2009;4:e5496. doi: 10.1371/journal.pone.0005496. PubMed DOI PMC

SCHMIDT MH. The energy allocation function of sleep: a unifying theory of sleep, torpor, and continuous wakefulness. Neurosci Biobehav Rev. 2014;47:122–53. doi: 10.1016/j.neubiorev.2014.08.001. PubMed DOI

SIEGEL JM. Sleep viewed as a state of adaptive inactivity. Nat Rev Neurosci. 2009;10:747–753. doi: 10.1038/nrn2697. PubMed DOI PMC

Van DONGEN HP, MAISLIN G, MULLINGTON JM, DINGES DF. The cumulative cost of additional wakefulness: dose-response effects on neurobehavioral functions and sleep physiology from chronic sleep restriction and total sleep deprivation. Sleep. 2003;26:117–126. doi: 10.1093/sleep/26.2.117. PubMed DOI

VYAZOVSKIY VV, CIRELLI C, PFISTER-GENSKOW M, FARAGUNA U, TONONI G. Molecular and electrophysiological evidence for net synaptic potentiation in wake and depression in sleep. Nat Neurosci. 2008;11:200–208. doi: 10.1038/nn2035. PubMed DOI

WIEBE ST, CASSOFF J, GRUBER R. Sleep patterns and the risk for unipolar depression: a review. Nat Sci Sleep. 2012;4:63–71. doi: 10.2147/NSS.S23490. PubMed DOI PMC

WISOR JP. The sleep-deprived hippocampus: a loss in translation. Physiol Genomics. 2013;45:26–27. doi: 10.1152/physiolgenomics.00156.2012. PubMed DOI

XIE L, KANG H, XU Q, CHEN MJ, LIAO Y, THIYAGARAJAN M, O’DONNELL J, CHRISTENSEN DJ, NICHOLSON C, ILIFF JJ, TAKANO T, DEANE R, NEDERGAARD M. Sleep drives metabolite clearance from the adult brain. Science. 2013;342:373–7. doi: 10.1126/science.1241224. PubMed DOI PMC

YAMAGUCHI M, UEMURA H, KATSUURA-KAMANO S, NAKAMOTO M, HIYOSHI M, TAKAMI H, SAWACHIKA F, JUTA T, ARISAWA K. Relationship of dietary factors and habits with sleep-wake regularity. Asia Pac J Clin Nutr. 2013;22:457–465. PubMed