Why We Sleep

WHY WE SLEEP The Functions of Sleep in Humans and Other Mammals J. A. Horne Published by Oxford University Press 1988 Contents CHAPTER 1 Introduction 1. 1Early Sleep Theories 1. 2Daily Sleep and Wakefulness 1. 3Measuring Sleep References CHAPTER 2 Sleep Deprivation 2. 1Problems with Animal Experiments 2. 2Recent Animal Experiments 2. 3Some Problems with Human Experiments 2. 41896 †The First Real Sleep Deprivation Experiment on Humans 2. 5The Longest Study †264 hours Without Sleep 2. 6Abnormal Behavior 2. 7The Longest Study With More than One Subject †205 hours 2. The Walter Reed Experiments 2. 9Motivation and Cerebral Impairment 2. 10Tasks Sensitive to Sleep Deprivation 2. 11Higher Levels of Cerebral Function 2. 12Spare Cerebral Capacity 2. 13Performance Measures Are Too Limited 2. 14Two Types of Sleepiness ? 2. 15Short-Term Sleep Restriction 2. 16Age and Sleep Deprivation 2. 17Does Repeated Deprivation Produce Immunity to Sleep Loss ? 2. 18Can Sleep Deprivation Effect s be Sped Up or Slowed Down ? 2. 19Do Long and Short Sleepers Differ in Their Recovery Sleep ? 2. 20Epilepsy 2. 21Other Effects On the Human EEGReferences CHAPTER 3 Physiological Effects of Sleep Deprivation 3. 1The First Major Physiological Study †Kleitman, 1923 3. 2The Next Fifty Years 3. 3Body Restitution and Sleep 3. 4Effects on Exercise 3. 5The Control of Body Temperature (Thermoregulation) 3. 6Other Aspects of Homeostasis 3. 7Update on Hormone Changes 3. 8The Immune System 3. 9Conclusions about Sleep Deprivation in Humans References CHAPTER 4 Body Restitution and Sleep 4. 1Tissue Restitution : Protein Turnover and Cell Division 4. 2Factors Influencing Protein Turnover and the Cell Cycle 4. Taking care of and Protein Turnover 4. 4Mitosis, Sleep and Physical Activity 4. 5Metabolism During Sleep and the Energy Cost of Restitution 4. 6Cell Energy Charge and Sleep 4. 7Human Growth Hormone Release During Sleep 4. 8Other Hormonal Changes During Human Sleep 4. 9Thyroid Activity a nd Sleep †Body Versus Brain Restitution 4. 10The Effects of Exercise on Sleep †Background 4. 11Is Body Heating the Key ? 4. 12Conclusions References CHAPTER 5 Waking Awareness, Subsequent Sleep, and Cerebral â€Å"Restitution† 5. 1Background 5. 2Influences of Wakefulness on Subsequent Sleep 5. SWS Changes throughout the Night, and â€Å"Models† of SWS 5. 4Brain Work During Wakefulness 5. 5Increased Awareness during Wakefulness and Subsequent Sleep 5. 6Reduced Sensory Stimulation during Wakefulness 5. 7SWS Reductions in Psychiatric Disorders 5. 8SWS and Aging 5. 9SWS Deprivation 5. 10Brain and Behavior During SWS 5. 11Cerebral Restitution During SWS ? 5. 12Sleep â€Å"Substances† and Immunoen hancement 5. 13Conclusions References CHAPTER 6 Core and Optional Sleep 6. 1Introduction 6. 2Natural Long and Short Sleepers among Humans 6. 3Can the Normal Sleeper Adapt to Less Sleep ? . 4Sleep Extension 6. 5Are We Chronically Sleep Deprived ? 6. 6The Circadian T iming of Sleep 6. 7Abnormalities in the Timing of Sleep 6. 8Insomnia 6. 9Stage 2 Sleep 6. 10Conclusions References CHAPTER 7 Sleep in Other Mammals 7. 1Dolphins 7. 2Laboratory versus Characteristic Habitats 7. 3Statistical Analyses of Mammalian Sleep 7. 4Sleep †the Immobilizer and Energy Conserver for Small Mammals 7. 5More Energy sparing if Sleep forms into a Torpor 7. 6Night versus Day Sleeping Mammals 7. 7Food, Feeding Behavior and Cerebral Development 7. 8Encephalisation 7. 9Conclusions so Far 7. 0Infancy References CHAPTER 8 REM Sleep 8. 1Perspectives on Dreaming 8. 2Memory, Homeostatic, Sentinel, and Motivational Theories 8. 3Abundance of REM Sleep in Early Life †The Ontogenetic Hypothesis 8. 4Sleep After Increased Learning 8. 5REM Sleep Deprivation in Animals †Background 8. 6REM Sleep Deprivation, Learning and Drive Behavior 8. 7REM Sleep Deprivation in Humans 8. 8Brain Protein Synthesis and Related Findings 8. 9Conclusions so Far 8. 10Similarities between REM Sleep and Wakefulness 8. 11Keeping Cool 8. 12Keeping Warm 8. 13Increased Heat Production without Shivering . 14Thermoregulation in REM Sleep Reverts to the Fetal Level 8. 15Conclusions About REM Sleep References Epilog Why Do We Sleep ? Section 1 INTRODUCTION This is a book about the reason for rest in vertebrates, especially in people. My methodology has been to take an expansive organic point of view, taking a gander at rest comparable to the normal ways of life and conduct of warm blooded animals, and making what I trust is a progression of educated assessments about what rest intends to them, and particularly to us. Obviously, I don't have the response to why we rest, as a lot of is still unknown.What I have endeavored to do is clean up numerous misguided judgments and attempt and comprehend what is left. This book isn't intended to be an exhaustive content on rest, yet a particular and individual record giving a few speculations about an assortment of viewpoints on rest. Huge n umbers of my decisions may well end up being incorrectly, as that is the method of most hypotheses. In any case, I trust that before they bomb they end up being useful in invigorating different thoughts. I have attempted to make the book discernible, and present my case inside a spreading out tale about sleep.Technicalities have been kept to a base, in spite of the fact that on occasion, and of need, it really expounds. At every possible opportunity, I have attempted to make it reasonable, as the book is pointed at rest specialists, yet at a readership having to a greater degree a passing enthusiasm for rest, with just an essential foundation in science and brain research. Little inclusion is given to the mind's neurophysiological and neurochemical components managing rest. While they help clarify how rest happens, the essential inquiries regarding what they are doing there in any case, that is the capacity of rest, despite everything must be answered.Besides, there are now amazing writings portraying these systems (e. g. ref. 1). Numerous individuals feel that, in spite of fifty years of examination, everything we can finish up about the capacity of rest is that it defeats drowsiness, and that the main dependable finding from lack of sleep tests is that rest misfortune makes us languid. Such a pitiful standpoint has been somewhat answerable for some rest analysts getting some distance from fundamental examination to the additionally animating field of rest issue. Moreover, is knowing why we rest such a fundamental inquiry all things considered ?Employment possibilities are far superior in the territory of rest issue, and there is the fulfillment of having the option to help or fix numerous patients. Various Sleep Disorders Centers have been set up in the United States and Europe in the course of the most recent decade (tsk-tsk, not in the UK), and this is by a long shot the best development region in rest research. While it could appropriately be contended th at rest issue is an unmistakably progressively beneficial territory for rest research, shockingly, similar to the neurophysiological systems of rest, it despite everything doesn't disclose to us much concerning why we sleep.Certainly, it has given important data about the neurophysiological components, and about the relationship among rest and breathing (which isn't generally identified with the capacity of rest either). This is the reason the book contains minimal about rest issue. Once more, there are as of now a few astounding records accessible (e. g. refs. 2-4). The point of this book is to show that we have not arrived at an impasse in our comprehension about the elements of rest, but instead, that we may have taken a lot for granted.As will be seen, this subject is as yet an obscure and energizing element, with numerous roads still to follow, and there is a lot of work to be finished. Compositions concerning why we rest go back to before the times of Aristotle. Most lounge ch air the motivation behind snooze terms of rest and recuperation from the â€Å"wear and tear† of alertness. One can't generally contend with this thought as it bodes well, what's more, we as a whole realize that we feel the â€Å"worse for wear† without rest, thus much better after rest. In any case it is an obscure thought †what precisely is recuperated ?This is as yet an issue for extensive discussion, as will be seen all through the book. It is usually felt that 7 †8 hours rest a night is essential. This thought is fortified from numerous quarters. For instance, by the well known press (â€Å"you must get your excellence sleep†), and by numerous GPs. Asking a patient â€Å"how are you dozing ? â€Å", may just be a stock expression for helping the GP to set up compatibility, yet it despite everything accentuates the requirement for a â€Å"good night's sleep†. The key indication of insuffient or upset rest is over the top languor in the day time.But numerous light sleepers don't encounter this, and a significant concern is about â€Å"not getting enough sleep†, and what may befall their wellbeing as a result. Be that as it may, we presumably don't generally require the most recent couple of hours of an average night's rest, and rest misfortune is far less unsafe than most would might suspect. The vast majority of the hypotheses about the capacity of rest focus on dreams or dreaming rest, these days called â€Å"rapid eye movement† rest (REM rest). Scarcely any glance at the rest of the rest. Numerous individuals accept that we just rest to dream or having REM sleep.Clearly, dreams are the most charming and noticable piece of rest, however the significance of this rest is likely overran ted. As will be seen, a huge segment of REM rest is superfluous, without sick impact. REM rest just possesses around one fourth of our daily rest, and to call the remainder of rest â€Å"non-REM† rest, by depicting i t as far as a nonappearance of REM rest, spoils most of rest, yet ignores what may losely be portrayed as the â€Å"deeper† part of non-REM rest, called â€Å"slow wave sleep† (SWS) in humans.This type of rest may well end up being the most pivotal for us. By the by, notwithstanding the way that nobody truly realizes what REM rest does, or whether it is â€Å"good† for us