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Sleep and Women's Health
Published in Michelle Tollefson, Nancy Eriksen, Neha Pathak, Improving Women's Health Across the Lifespan, 2021
Sleep is divided into non-rapid eye movement (non-REM) and REM sleep stages. Non-REM sleep is further divided into stages 1, 2, and 3. Normal sleep is comprised of 4–6 cycles through the different stages of sleep. Stage 1, the “dozing off” period, usually lasts for 1–5 minutes. Stage 2, or light sleep, makes up about 50% of total sleep time and is characterized by a slowing of brain activity; reduction in body temperature, breathing, and heart rate; and relaxation of muscles. Stage 3 is the deepest sleep, normally 20% of total sleep time, characterized by further muscle relaxation and slowing of heart rate and breathing. Stage 3 is more prevalent in the first half of the night, reduces homeostatic sleep drive, and is involved in memory consolidation, insight and creativity.15 Slow-wave sleep in stage 3 affects fluid dynamics in the cerebrospinal fluid, increasing flow through the glymphatic system that regulates removal of amyloid-beta and tau.16 Each sleep cycle usually concludes with time in REM, with increasing time in REM the second half of the night. During REM, brain activity picks up while muscles lose their tone (except the eyes and diaphragm). REM plays a role in memory consolidation and motor function.
What are dreams, and how do we study them?
Published in Josie Malinowski, The Psychology of Dreaming, 2020
Human sleep is split into two main stages: rapid eye movement (REM) sleep, and non-REM sleep. Non-REM sleep is further divided into three more stages: Stage 1, Stage 2, and Stage 3. These different stages are characterised by various changes in the brain and body.
Consciousness, EEG, Sleep and Emotions
Published in Peter Kam, Ian Power, Michael J. Cousins, Philip J. Siddal, Principles of Physiology for the Anaesthetist, 2020
Peter Kam, Ian Power, Michael J. Cousins, Philip J. Siddal
REM sleep lasts for 5–30 minutes and occurs approximately every 90 minutes during sleep. Adults aged more than 50 years spend about 15% of total sleep in REM sleep. REM sleep is divided into phasic and tonic phases. The tonic phase, associated with tonic inhibition of muscle tone, is interrupted by a phasic phase, which is associated with motor activity (e.g. rapid eye movements), autonomic instability (irregular respiration, hypo-or hypertension) and dreaming.
EEG coherence and power spectra during REM sleep related to melatonin intake in mild-to-moderate Alzheimer’s disease: a pilot study
Published in International Journal of Neuroscience, 2023
Manuel Alejandro Cruz-Aguilar, Ignacio Ramírez-Salado, Marisela Hernández-González, Miguel Angel Guevara, Ana Paula Rivera-García
There is a growing body of research on humans and animals that provides evidence for a prominent role of REM sleep in memory consolidation [17, 43]. Thus, it is important to test pharmacological alternatives that may improve the clinical conditions of REM sleep in AD patients. For this reason, the aim of the present study was to determine the effect of melatonin on EEG activity and the degree of EEG synchronization between different cortical areas during REM sleep in AD patients who received melatonin. Considering that melatonin reduces brain electrical activity by modulating GABAA receptors [31–35], that GABArgic activity is required for REM sleep generation [23–27], and that melatonin intake in AD patients reduces REM sleep latency [37], we hypothesized that the facilitator effect of melatonin on REM sleep onset will be associated with a lower percentage of fast frequencies (in β and γ) and a decrease in the degree of EEG synchronization (coherence) between cortices in these same fast frequencies. To test these hypotheses, we evaluated the effects of melatonin on REM sleep latency, EEG spectral power, and EEG coherences during the first nocturnal episode of REM sleep in a group of mild-to-moderate AD patients previously treated with melatonin [41, 42].
Sleep is something, not nothing: an interprofessional approach to sleep assessment and treatment to support substance use recovery
Published in Journal of Social Work Practice in the Addictions, 2023
Jennifer Gardner, Margaret Swarbrick, Robert H. Kitzinger
Other basic sleep definitions that are of importance to this topic include circadian rhythm, rapid eye movement (REM) vs. non-rapid eye movement (non-REM) sleep and sleep onset latency. Circadian rhythm is defined as the physiological 24-hr time pattern of human life, which includes periods of consciousness/alertness and sleep. This pattern is established early in life through consistent patterning of waking/sleeping, therefore is contextual in nature (Meadows et al., 2017). Sleep progresses through predictable stages of non-rapid eye movement (NREM) and rapid eye movement (REM) sleep, with the majority of sleep as NREM. Although REM constitutes less time during a sleep cycle, it does involve high brain activity and is associated with restoration. Sleep onset latency is in essence the ‘time from turning off the light to falling asleep,’ or the time it takes to fall asleep from consciousness. These terms will be important to understand to guide professionals when engaging in assessment and intervention.
D-ribose-L-cysteine modulates paradoxical sleep deprivation-induced neurological impairments: anxiolytic and antioxidative study in rat model
Published in Egyptian Journal of Basic and Applied Sciences, 2022
Taiwo Abayomi, Olorunfemi Tokunbo, Oluwatobiloba Oroyemi, Olawale Abayomi, Opeyemi Osuntokun, Benedict Falana, Temidayo Adeniyi
Sleep is a ubiquitous phenomenon and most species, including humans spend a significant time asleep. It is widely acknowledged that sleep is crucial for proper brain function. There are five phases of sleep: the wake phase, non-rapid eye movement (NREM) phase, which has 3 stages (N1 to N3), and the rapid eye movement (REM) phase. Wakefulness is characterized by more than 50% alpha waves and opening of the eyes. The N1 stage of the NREM phase is the most superficial stage of sleep characterized by skeletal muscle tone and regular breathing rate. The N2 stage, where the majority of sleep is spent, typifies a deeper stage of sleep characterized by lowered body temperature and heart rate. As deeper sleep develops, there is a transition to the N3 stage of NREM. This is the deepest stage of sleep when the body repairs worn-out tissues, builds bones and strengthens the immune system. REM sleep usually begins about 90 minutes after an individual falls asleep. Apart from the eye and diaphragmatic breathing muscles which remain active, all other skeletal muscles are inactive. The REM stage of sleep is characterized by dreaming and erratic breathing rate [1].