Sleep: Biological Clocks, Functions, and Phases

Sleep is a vital function of the nervous system, involving slow-wave sleep for restoration and REM sleep for information processing.

### The Science of Sleep: From Biological Clocks to Sleep States
* 🧠 Sleep is a fundamental state of the nervous system necessary for the brain to **rest and restore resources**.
* 🌞 Biological clocks, located in the brain's suprachiasmatic nuclei, regulate circadian rhythms based on the **Earth's day-night cycle**.
* ⏰ It is important to maintain a regular sleep schedule to align with **individual circadian rhythms**.
* 😴 Slow-wave sleep, characterized by **delta waves**, is a restorative phase that primarily **replenishes resources**.
* 🌈 REM (rapid eye movement) sleep, also known as paradoxical sleep, is an active brain state where **information processing and memory consolidation** occur.
* 👶 The amount of REM sleep is higher in infants and varies based on the **novelty of daily experiences**.
* - Chronotype, the individual preference for sleep timing, is influenced by **genetic factors**.
* 📈 The molecular mechanism of the circadian clock involves the interaction of **"period" genes and proteins**.
* 🦑 REM sleep is observed in birds and mammals, and there is evidence to suggest that cephalopods like octopuses also experience **similar dream-like states**.

### Sleep: The Brain's Vital Restorative Process
* 🧠 The reticular nuclei in the brainstem serve as the **main wakefulness center**, integrating all information and setting the brain's tone. The wakefulness center in the medulla oblongata responds to the body's chemical composition, **influencing the timing of sleep**.
* 💤 Slow-wave sleep facilitates waste removal from the brain, maintaining homeostasis. The brain's glymphatic system clears waste by **reducing the volume of glial cells** during slow-wave sleep.
* ❤ Slow-wave sleep optimizes the functioning of various body systems, such as the **gastrointestinal and cardiovascular systems**. Sleep deprivation can lead to a decline in **immunity and overall body functions**.
* 🧙 Dreams involve working with accumulated information and are often a **creative process**. The hippocampus plays a crucial role in **transferring information to long-term memory** during REM sleep.
* 😴 The optimal sleep schedule varies based on individual factors such as **physical activity, diet, and age**. It is essential to **listen to your body and adjust accordingly**.
* ☕ Caffeine acts as an adenosine receptor antagonist, **blocking the effects of fatigue**. The number of adenosine receptors in the brain varies among individuals, affecting caffeine's **impact on sleep**.
* 📝 "It is more constructive to **understand and adjust to your body's unique needs**. Like good teachers say when managing a poorly behaving class, you have to become the '**main brain**' among them."
* 😊 "If you are approximately the same, it will work for you too. If you are different, you need to find a **different teacher who is similar to you** or listen to **15 teachers and create your own system**."

Лекторий ЭФКО. «Мозг и сон. Сон как самый недооценённый ресурс управления жизнью» – Вячеслав Дубынин

🌏 Перерабатываем масличные
🌏 Развиваем экспорт
🌏 Создаем инновации
🌏 Производим еду будущего
🌏 Строим бизнес про человека


Группа Компаний ЭФКО

The Importance of Sleep from a Neurobiologist's Perspective

Sleep is a crucial function of the nervous system, allowing for the restoration of resources in the brain due to its high energy consumption.

The intricate network of 90 billion neurons in the brain is responsible for various functions, including sleep and wakefulness.

The sleep-wakefulness centers in the brain play a vital role in providing energy to all the brain's networks, and any disruption in these centers can have widespread consequences.

The Significance of Sleep and Wakefulness

Homeostasis is crucial for the body to function normally, including the regulation of sleep and wakefulness.

The ancient Greeks recognized sleep as consisting of two states: rest, controlled by Hypnos, and dreaming, controlled by Morpheus.

The recommended amount of sleep for different age groups is based on decades of observation, with 7-9 hours for adults being strongly recommended.

Oversleeping can also lead to health issues, so the ideal range is from 6 to 9 hours of sleep.

Sleep is best measured in cycles, with 4 cycles (6 hours), 5 cycles (7.

5 hours), and 6 cycles (9 hours) being the ideal scenarios.

Consistent sleep schedule is crucial for regulating the body's biological clock.

A comfortable sleep environment, including a good mattress and minimal noise, is essential for quality sleep.

Avoiding screens before bed and monitoring food and caffeine intake can significantly impact the ability to fall asleep and the quality of sleep.

The Significance of Short Naps for Brain Function

Taking a 20-minute nap can improve brain function by reducing extra noise.

The nap should be short to avoid deep sleep, as longer naps can cause significant inhibition.

Our biological clocks are tied to the day-night cycle, with cortisol for wakefulness and melatonin for sleep, and are regulated by super nuclei in the anterior hypothalamus.

These super nuclei are located strategically in response to the level of illumination and are the most ancient structure of the vertebrate nervous system.

The Role of Circadian Rhythms in Different Organisms

Lancelets rely on light-sensitive cells to regulate their activities and have a system similar to vertebrate brains.

Secondary biological clocks in internal organs can maintain daily rhythms, independent of light exposure.

The 2018 Nobel Prize in Physiology and Medicine was awarded for the discovery of the molecular mechanism behind the 24-hour cycle, involving specific genes and proteins.

The Molecular Basis of Chronotype and Biological Clocks

The concentration of proteins follows a 24-hour cycle, impacting an individual's chronotype and response to sleep deprivation and time zone changes.

The discovery of this molecular process in Drosophila and vertebrates, including humans, has led to a better understanding of genetic predispositions for dealing with unstable routines and sleep issues.

The classification of electroencephalogram waves, from alpha to delta waves, reflects different brain states during wakefulness and sleep, providing insight into neuronal activity and synchronization.

Delta rhythms indicate deep sleep and should not be present in adults during wakefulness, potentially signaling trauma or other issues.

The sleep cycle consists of slow-wave sleep, which is a restorative phase, and REM sleep, where the brain is active and processes information.

REM sleep is influenced by the individual's experiences during the day and is longer in children, playing a crucial role in memory consolidation.

This sleep pattern is observed in birds, mammals, and possibly cephalopods, indicating its significance in the evolution of brain function and memory.

The Brain's Role in Wakefulness and Sleep Cycles

The brainstem houses the main wakefulness center, which integrates sensory signals and sets the brain's tone for activity.

Serotonin signal from the brainstem inhibits the cerebral cortex activity during slow-wave sleep, while the release of norepinephrine during REM sleep triggers eye movement but shuts down major muscle tone.

The main purpose of slow-wave sleep is to facilitate waste removal from the brain, and the recently discovered brain lymphatic system plays a crucial role in this process by clearing away harmful molecules.

The Impact of Sleep on Brain Function and Overall Health

During slow-wave sleep, the brain's glymphatic system is activated, allowing for the removal of waste and toxins, which is crucial for preventing conditions like Alzheimer's disease.

Slow-wave sleep also plays a vital role in the restoration of the brain and internal organs, optimizing the body's different systems and promoting overall health.

Sleep deprivation not only affects brain function but also leads to severe disruptions in the functioning of internal organs, immune system, and hormonal regulation, emphasizing the importance of adequate sleep for overall well-being.

The Impact of REM Sleep on Memory Consolidation

The process of memory consolidation involves the transfer of information from short-term to long-term memory, with the hippocampus playing a crucial role.

The phenomenon of hippocampal overload can lead to the erasure or rewriting of new information, impacting the formation of long-term memories.

REM sleep is essential for the rewriting and strengthening of memory pathways, serving as a critical phase for memory consolidation and emotional processing.

The Role of Sleep in Problem Solving and Decision Making

The brain's competition between wakefulness and sleep centers can lead to problem-solving and decision-making processes.

The chemical composition of the blood and sensory signals also play a crucial role in regulating the sleep-wake cycle.

The adaptive nature of the body's response to sleep, as seen in the Pirahã tribe's sleeping habits, highlights the flexibility of sleep patterns.

The Impact of Sleep on Brain Function and Performance

The text discusses the importance of carefully monitoring and prioritizing brain function for optimal performance, suggesting not to experiment with sleep patterns.

It also highlights the shift in the balance of excitation and inhibition in the brain with fatigue, affecting the quality of sleep.

The text explores historical and modern sleep patterns, emphasizing the need to choose and stick to a consistent sleep routine for the benefit of biological clocks and overall brain plasticity.

Biological clocks can vary among individuals, causing some to have shorter or longer days than the standard 24-hour cycle, and a few may even switch to a pattern of infant sleep.

Remembering dreams is rare for most people, but keeping a dream journal can help capture creative ideas and problem solutions.

Lucid dreaming, while intriguing, can lead to sleep deprivation if not managed properly.

This text discusses the variability of biological clocks, the potential benefits of keeping a dream journal, and the possible consequences of lucid dreaming.

The Significance of Yawning in Communication and Emotions

Yawning in monkeys is a form of communication, indicating boredom or lack of fear.

Yawning is contagious due to mirror neurons that react to emotions, similar to the way facial expressions mimic others.

The function of yawning is not fully understood, but it is believed to be related to various factors, including eating and the body's unique needs.