Sleep has always been an intriguing question since we spend much of our lives sleeping, so it is of interest to many scientists to find out what exactly the function of sleep is. Sleep is defined as a natural state of mind and body characterized by altered, relatively inhibited consciousness. The state in which our senses are disconnected. Sleep is exquisitely regulated, there are complex mechanisms in our brain that increase the duration or depth of sleep after sleep deprivation to allow some of what has been lost to be recovered, a phenomenon called homeostatic regulation. Sleep mechanism: – There are also neural mechanisms that tend to consolidate sleep in a certain phase of the 24-hour cycle which is circadian regulation. To understand sleep it is necessary to address two distinct aspects of it. These are sleep times and sleep duration/quality. Say no to plagiarism. Get a tailor-made essay on "Why Violent Video Games Shouldn't Be Banned"? Get an Original Essay Both are kept pretty much the same from day to day. Sleep timing is well established as a function of the circadian system in the brain. The circadian system is important for driving many aspects of behavior and physiology with a period of approximately 24 hours through a series of molecular oscillators. How our bodies know how much sleep we need is less understood. Based on rebound sleep, or compensatory sleep, that follows sleep deprivation, sleep is believed to be an essential process whose quantity is controlled by a homeostatic system. Now the question is: why has natural selection favored sleep since it puts the individual in a rather dangerous situation because it reduces the ability to respond promptly to stimuli that signal a threat and also reduces the time spent searching for food, reproducing or monitoring the 'environment. So there must be a strong sleep-related function that makes it so important. Many groups are working to develop different levels of sleep functions, one of which is related to synaptic plasticity. The genes involved in sleep are ABCC9, DEC2, PAX8, VRK2. Importance of sleep It has been seen that sleep is linked to synaptic modulation and memory. Researchers began mapping the general circuits that control wakefulness and sleep more than 50 years ago, and in the last 10 to 20 years much has been learned about the specific systems that regulate sleep states (REM and non-REM sleep). Other new work has examined the ways in which behavioral drives, including homeostatic, circadian, and allostatic influences, can influence these switching mechanisms. Sleep has been identified as a state that optimizes the consolidation of newly acquired information in memory, depending on the specific learning conditions and timing of sleep. Consolidation during sleep promotes both quantitative and qualitative changes in memory representations. Sleep involves various neuronal connections. Mutations in any of the circadian-related genes can affect the amount of sleep and, as a result, other problems that can arise due to sleep deprivation. Background: The invertebrate whose sleep has been most intensively studied is the fruit fly Drosophila melanogaster. The fact that the fruit fly displays all the major behavioral properties of sleep has generated great excitement and implies that sleep may have been present in the common ancestor of arthropods and vertebrates. The fruit fly central nervous system has over 200,000 neurons and has no anatomical structures that clearly correspond to their fruit fly counterparts..