Read below to find information about the benefits of engaging in sleep, the consequences of sleep restriction, and its relationship with your nervous system.
Despite the importance that people attribute to the role of sleep in our lives, many do not understand its relationship with the brain and body.
In addition to offering a host of protective factors, sleep provides our bodies with the opportunity to engage in deep, holistic (mental, emotional, behavioral, cognitive, physical, spiritual) processing and healing. Due to the bidirectional nature of nervous system regulation and sleep, many studies have highlighted the benefits of sleep to include ensuring metabolic homeostasis, improvement in memory recall, neuronal detoxification, enhanced immunity, reduction of mental fatigue, tissue restoration, improved immunity, enhanced removal of neurotoxic waste product, increasing cerebrospinal fluid flow, conservation of brain energy, and removal of beta-amyloid metabolite in the brain, which is responsible for many neurodegenerative diseases including dementia and Alzheimer’s Disease.
Sleep works as a garbage disposal for the brain - cellular waste byproducts accumulate throughout the day, and are removed via cerebrospinal fluid as a product of the glymphatic system’s work during the night. The brain cannot multitask in performing both sensory information processing and cellular waste product clearance simultaneously. Allowing the brain to take a pause in sensory input to process cellular waste product is integral to supporting its function, and consequently mental, physical, cognitive, and emotional wellness.
While sleeping, the brain is able to reorganize itself, recharge itself, remove toxic waste, consolidate learning and memory, and engage in information processing (cortical hyperarousal limits this in those with insomnia). This includes emotional processing, emotional management, and emotional responses. During sleep, the brain engages in habituation processes that allow the brain to reduce aversive reactions to previously perceived stressful stimuli.
Furthermore, reparative enzymes are released during sleep to restore brain cell damage caused by free radical exposure. Without sleep, the brain is unable to function optimally due to the neurotransmitters and neurons that do not get to be repaired or regenerated.
When sleep deprivation is extended across multiple days, this phenomena worsens, with neurons degenerating due to constant activation. A lack of sleep results in a lack of regeneration and rest time for neurons that eventually become worn out. Moreover, upon experiencing sleep deprivation, the body is unable to perform processes required of the glymphatic system, resulting in the build up of toxins that affect the body physically and result in declines in judgment, behavior, and cognitive abilities.
Extensive literature has found sleep deprivation to be linked to premature mortality and increased risk factors, including an increased prevalence of cardiovascular disease development, anxiety, defiance, depression, heart attacks, susceptibility to frustration, daytime sleepiness, hyperlipidemia, hypertension, pain sensitivity, obesity, risk of cancer development, rigidity in thinking, risk of diabetes development, cholesterol, risk of injury, risk of car accidents, cardiovascular morbidity, inflammation, chronic pain, insulin resistance, frequency of migraines, burnout, irritability, and fatigue.
Experimentally reducing sleep duration in otherwise healthy individuals has been associated with impaired glucose homeostasis, indicating a potential link between insufficient sleep and metabolic disturbances, particularly related to glucose regulation. Chronic sleep restriction has also been linked to decreased metabolic activity, effectiveness in decision making, attention span, motivation, organizational skills, motivation, reaction time, vigilance, mood, cognition, memory, executive function, visuomotor performance, NREM sleep (slow-wave, deep, restorative rest), and can compromise dietary interventions. Why is this?
Each stage of sleep optimally rejuvenates and restores the brain at different levels and for different functions. Many studies have demonstrated the value that NREM sleep holds in turning off the norepinephrine, serotonin, and histamine neurotransmitters, lending the opportunity for receptors to “rest” and regain sensitivity. Thus, engaging in NREM sleep allows the brain to reset neurotransmitter receptors, heightening their sensitivity. At naturally produced levels, these neurotransmitters are then increased in effectiveness. *Nervana sequences are thus especially beneficial in combating the consequences of the overstimulation and overconsumption that modern-day technology has introduced.
As modern science catches up to understanding the role and value of sleep, and the dangerous consequences of sleep deprivation, it is integral that people increase their awareness of the subject, and become better equipped to support their body’s sleep hygiene, habits, and quality.
Slow-Wave/NREM
What is NREM?
Deep nonrapid eye movement (NREM) sleep, or slow wave sleep (SWS) is widely recognized as the most restorative stage of sleep, closely linked to sleep quality and maintenance. In addition to showing up on EEG as brain states, slow wave activity (SWA) is crucial in supporting maintenance of physiological health as well, including autonomic nervous system functions such as endocrine and cardiovascular markers. SWS fosters the highest rate of human growth hormone secretion and an autonomic nervous system shift from a sympathetic to parasympathetic activation. A disruption in SWA, even as few as three nights’ SWS deficit, reduces autonomic balance and reduces the autonomic nervous system’s ability to regulate glucose, resulting in reduction in insulin sensitivity. The association between disrupted SWA and heightened diabetes risk is considered to be mediated by the effects of SWA reduction on the nervous system.
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