On the Function and Evolution of Sleep

and cognitive function. These findings have led to a robust exploration in the science of sleep

Organisms, whether they happen to be nocturnal or diurnal always have a sort of involuntary or in the words or Ivan Pavlov, ‘unconditioned reflex responses’ that they use to determine when to sleep and wake. Biologists universally believe that organisms have a type of biological clock controlling their various cycles for daily activities. According to the American Heritage’s Dictionary of Student Science, 2014, the daily biological activities are referred to as circadian rhythms and are influenced by light and dark 24-hour day regular intervals. The rhythms are controlled by hormones and regulated by the brain, but can be disrupted by the alteration of daily schedules like exposure to light during night time hours. (American Heritage, 2014). Different organisms have different ways of handling their sleep-wake cycles as we will see in the analysis of cycles that are characteristic of the giraffe, the camel, and the desert snail. This paper will analyze sleep patterns of each organism, how different their sleep cycle is from that of the human cycle, whether they are nocturnal or diurnal, and whether any of them dreams.

Studied actually show that only when we do sleep certain genes in the brain refurbish and rebuild in a sequence of chemicals reaction.

Sleep is considered to be one of the most important processes that living organisms do, but there is a lot that remains unknown about its true function in the brain. The Wen-Bio Gan Group conducted a study on the effects of sleep and dendritic spine formation after motor learning.

Modern Technology has helped make the study of sleep economical and easier due to which various studies have been carried out on sleep. And hence experts call this “the dawn of the golden age of sleep research” and ironically the question arises “If this is sleep research’s golden age, then why are we all so tired?” In addition to this the

The human brain is complex and the way the body advances is through sleep. Sleep allows the body to rest, repair and rejuvenate itself. The brain is responsible for wave patterns called alpha and beta waves that through a series of stages, produces what we know as non-rapid eye movement (NREM), and rapid eye movement (REM) sleep.

The second biological system related to sleep is the circadian alerting system, or the “sleep clock.” It regulates the timing of wakefulness and sleepiness during our day. You may know this as your biological day/night rhythm. It is controlled by the relationship between structures in the brain and light, and our energy use during the day. The structure that is responsible for this called the suprachiasmatic nucleus (SCN) in the hypothalamus. The circadian alerting system sends “alerting signals” during the day and turns those signals down at night. In this way, it runs on a 24-hour cycle.

explicit, and non-declarative, i.e. procedural or implicit, memory in man. Sleep is composed of two prominent stages, namely REM sleep and NREM sleep, the latter being subdivided into SWS and Stage 2 sleep in humans. These stages of sleep differ by many factors including their temporal distribution and regulation, the pattern of neuronal activity, the specific neurotransmitter and neurochemical changes, and regional brain activity. Up to now, four experimental approaches have been used to test the hypothesis of the processing of memory traces during sleep: (1) the effects of post-training sleep deprivation on memory consolidation, (2) the effects of learning on post-training sleep, (3) the effects of within sleep stimulation on the sleep pattern and overnight memories, and (4) the re-expression of behavior-specific neural patterns during post-training sleep. These studies, which we review here, actually suggest that REM and NREM sleep stages could have memory-related functions. On this basis, not all types of memories seem to rely on the same stage of sleep for

As we all know, one third of our life is spent to sleep, but very few people intend to lay bare the secret of that. There would be a question: why do we sleep? According to the video "The Function of Sleep", Tyson states that people are not very clear about the purpose of sleep, but some researchers believe that sleep could enhance memory. MIT researcher Matthew Wilson also illustrates the thoughts of a rat can be read by implanted the electric wire into its brain. According to a special project "rat maze", memory not only affects the rat finds the way with same pattern, but also generates the main part of its dreams. The video also concludes that the function of sleep is learning and memory, and it is not just a

The unanswerable question “Why do we sleep?” has had scientist vigorously studying the human brain and the components beneficial to sleep. With many studies, such as sleep deprivation among different species, as well as sleep patterns among different species. Concluding this research there was no pattern amongst the different species,

Heller’s two main research focuses are the biology of sleep and the biology of thermoregulation. Understanding how sleep and circadian rhythms work has obvious implications for treating sleep disorders and the many health issues associated therewith, and, Heller has shown, less obvious implications for treating issues with memory, as well as diseases, such as Down syndrome, that are related to impacted circadian rhythms and memory formation and retainment. Understanding how body temperature affects body functions has practical applications to human health and the treatment of hypo- and hyperthermia--problems that will likely impact more and more people as climate change gives rise to more extreme temperatures across the globe. In addition, research in thermoregulation has practical applications for athletes who would like to improve their performance by ameliorating the negative impacts of high body temperature on physical functioning.

What is sleep? The dictionary definition of sleep is as follows, “a condition of body and mind such as that which typically recurs for several hours every night, in which the nervous system is relatively inactive, the eyes closed, the postural muscles relaxed, and consciousness practically suspended,” (Definition). While this is undoubtedly true, there is so much more on the mystery of sleep. For many years people have wondered and debated on why humans sleep. There used to be many theories on why humans slept. With more advanced technology and stronger research many have been ruled out. In today’s society there are three commonly accepted, but debated, theories on

 A most popular theory on why we sleep is the restorative theory of sleep:

A possible purpose for sleep is that decreased responsiveness allows the brain to undergo "dynamic stabilization," or DS, which is essentially the activation of synapses in neural circuits of the cerebral cortex to enhance and maintain neural functioning (2) . Generally, DS does not initiate the activation of a neural circuit because of extensive inhibition of the motor neurons, and is therefore "non-utilitarian", meaning that there are no visible physical results (2) . DS can occur during consciousness, but the cerebral complexity of warm-blooded vertebrates requires more DS than can occur simultaneously with the processing necessary for waking thought and perception. Sleep thus evolved to provide the brain with a condition virtually free from external distraction (2) .

Comprehending these theories can help expand our appreciation of the function of sleep in our lives.