{"id":604,"date":"2025-02-21T23:27:54","date_gmt":"2025-02-21T21:27:54","guid":{"rendered":"https:\/\/evolutionandsecurity.com\/?p=604"},"modified":"2025-12-29T13:29:15","modified_gmt":"2025-12-29T11:29:15","slug":"loosing-and-awaking-heartbeat-what-is-sleep-in-real","status":"publish","type":"post","link":"https:\/\/evolutionandsecurity.com\/?p=604","title":{"rendered":"Losing and awakening heartbeat. What is sleep in real?"},"content":{"rendered":"<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-606 size-large\" src=\"https:\/\/evolutionandsecurity.com\/wp-content\/uploads\/2025\/02\/NA-fluctuations-Neurongr4_lrg-1024x591.webp\" alt=\"\" width=\"1024\" height=\"591\" srcset=\"https:\/\/evolutionandsecurity.com\/wp-content\/uploads\/2025\/02\/NA-fluctuations-Neurongr4_lrg-1024x591.webp 1024w, https:\/\/evolutionandsecurity.com\/wp-content\/uploads\/2025\/02\/NA-fluctuations-Neurongr4_lrg-300x173.webp 300w, https:\/\/evolutionandsecurity.com\/wp-content\/uploads\/2025\/02\/NA-fluctuations-Neurongr4_lrg-768x444.webp 768w, https:\/\/evolutionandsecurity.com\/wp-content\/uploads\/2025\/02\/NA-fluctuations-Neurongr4_lrg-1536x887.webp 1536w, https:\/\/evolutionandsecurity.com\/wp-content\/uploads\/2025\/02\/NA-fluctuations-Neurongr4_lrg-2048x1183.webp 2048w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><\/p>\n<p style=\"box-sizing: border-box; margin: 0px; padding: 0px;\">By Marta Kobla\u0144ska, February 21, 2025 Photo: This model suggests that the physiological processes influenced by fluctuations in norepinephrine (NA) during NREM sleep\u2014particularly those related to memory consolidation and glymphatic clearance\u2014function best when these fluctuations occur approximately every 50 seconds. Authors: <strong>Anita L\u00fcthi, Maiken Nedergaard.<\/strong><\/p>\n<p lang=\"en-US\"><strong><span style=\"color: #2e2e2e;\"><span style=\"font-family: Liberation Serif, serif;\"><span style=\"font-size: x-large;\">Sleeping is a kind of disengagement from the environment to restore energy released earlier. Fragmented sleep harms cognition and health. At the same time, seconds of a wake-like state due to noradrenaline inflows leave us ready to wake up.<\/span><\/span><\/span><\/strong><\/p>\n<p><span style=\"font-family: Liberation Serif, serif;\"><span style=\"font-size: x-large;\"><span style=\"color: #2e2e2e;\"><span lang=\"en-US\">I<\/span><\/span><span style=\"color: #2e2e2e;\"><span lang=\"en-US\">t is obvious that sleep is crucial for our daily life, memory, and cognition, as well as <\/span><\/span><span style=\"color: #2e2e2e;\"><span lang=\"en-US\">strengthens resilience against disease, including mental disorders<\/span><\/span> <span style=\"color: #2e2e2e;\"><span lang=\"en-US\">and age-related neurodegeneration. <\/span><\/span><span style=\"color: #2e2e2e;\"><span lang=\"en-US\">Good sleep enable<\/span><\/span><span style=\"color: #2e2e2e;\"><span lang=\"en-US\">s<\/span><\/span><span style=\"color: #2e2e2e;\"><span lang=\"en-US\"> long-term well-being. <\/span><\/span><span style=\"color: #2e2e2e;\"><span lang=\"en-US\">Its disruption leads to various problems, while the reasons for commonly shared insomnia may differ individually, <\/span><\/span><span style=\"color: #2e2e2e;\"><span lang=\"en-US\">despite<\/span><\/span><span style=\"color: #2e2e2e;\"><span lang=\"en-US\"> the lesion of pathways <\/span><\/span><span style=\"color: #2e2e2e;\"><span lang=\"en-US\">being<\/span><\/span><span style=\"color: #2e2e2e;\"><span lang=\"en-US\"> similar, as mammalian sleep <\/span><\/span><span style=\"color: #2e2e2e;\"><span lang=\"en-US\">patterns <\/span><\/span><span style=\"color: #2e2e2e;\"><span lang=\"en-US\">seem to resemble the same key <\/span><\/span><span style=\"color: #2e2e2e;\"><span lang=\"en-US\">marks<\/span><\/span><span style=\"color: #2e2e2e;\"><span lang=\"en-US\">. These are brain waves, the amount of oxygen in the blood, <\/span><\/span><span style=\"color: #2e2e2e;\"><span lang=\"en-US\">the <\/span><\/span><span style=\"color: #2e2e2e;\"><span lang=\"en-US\">speed of the heart and breath, <\/span><\/span><span style=\"color: #2e2e2e;\"><span lang=\"en-US\">eyes, and limb movements<\/span><\/span><span style=\"color: #2e2e2e;\"><span lang=\"en-US\">. <\/span><\/span><span style=\"color: #2e2e2e;\"><span lang=\"en-US\">But now, scientists of Switzerland and Denmark in a new study<\/span><\/span><span style=\"color: #2e2e2e;\"><span lang=\"en-US\"><b>,,Anything but small: Microarousals stand at the crossroad between noradrenaline signaling and key sleep functions, <\/b><\/span><\/span><span style=\"color: #2e2e2e;\"><span lang=\"en-US\">\u201c published in <\/span><\/span><span style=\"color: #2e2e2e;\"><span lang=\"en-US\"><b>,, Neuron\u201d<\/b><\/span><\/span><span style=\"color: #2e2e2e;\"><span lang=\"en-US\"> demonstrate connections between wake-like brain activity, changes in the heart and respiration, and movements of various body parts. <\/span><\/span><span style=\"color: #2e2e2e;\"><span lang=\"en-US\">Simultaneously, wake-like brain activity lasting seconds and corresponding body movements do not imply that microarousals are simply sleep-disrupting events.<\/span><\/span><\/span><\/span><\/p>\n<h2><strong><span style=\"font-family: Liberation Serif, serif;\"><span style=\"font-size: x-large;\"><span style=\"color: #2e2e2e;\">A<\/span><span style=\"color: #2e2e2e;\">re we going away and back?<\/span><\/span><\/span><\/strong><\/h2>\n<p lang=\"en-US\"><span style=\"color: #2e2e2e;\"><span style=\"font-family: Liberation Serif, serif;\"><span style=\"font-size: x-large;\">Our heart is separate from the brain system of signals; however, both of them work synchronously, being part (in the case of brain-selected structures) of the sympathetic system in the body. The system is responsible for, in general, action excluding the intestinal tract. The trigger to enable action is noradrenaline, a hormone that accelerates heart speed and thus blood pressure at the same time releasing glucose stored in cells, which gives an energy boost.<\/span><\/span><\/span><\/p>\n<p lang=\"en-US\"><span style=\"color: #2e2e2e;\"><span style=\"font-family: Liberation Serif, serif;\"><span style=\"font-size: x-large;\">\u00a0&#8211; <em>With the example of rodents, we indicated natural sleep arousal events timed to fluctuations in neuromodulatory tone, particularly noradrenergic signaling driven by the locus coeruleus (LC), <\/em><\/span><\/span><\/span><span style=\"font-family: Liberation Serif, serif;\"><span style=\"font-size: x-large;\"><span style=\"color: #2e2e2e;\"><span lang=\"en-US\">say <\/span><\/span><strong><span style=\"color: #2e2e2e;\">Anita<\/span><span style=\"color: #2e2e2e;\">\u00a0<\/span><span style=\"color: #2e2e2e;\">L\u00fcthi <\/span><span style=\"color: #2e2e2e;\">of the University of Lausanne and Maiken Nedergaard of the University of Copenhagen and Rochester.<\/span><\/strong><\/span><\/span><\/p>\n<p><span style=\"color: #2e2e2e;\"><span style=\"font-family: Liberation Serif, serif;\"><span style=\"font-size: x-large;\"><span lang=\"en-US\">T<\/span><span lang=\"en-US\">he locus coeruleus is <\/span><span lang=\"en-US\">located in the brainstem. <\/span><span lang=\"en-US\">The brain trunk<\/span><span lang=\"en-US\"> represents the most primo<\/span><span lang=\"en-US\">r<\/span><span lang=\"en-US\">d<\/span><span lang=\"en-US\">i<\/span><span lang=\"en-US\">al <\/span><span lang=\"en-US\">part of our brain <\/span><span lang=\"en-US\">that<\/span><span lang=\"en-US\"> sustains basic life functions. <\/span><span lang=\"en-US\">According to the scientists, a<\/span><span lang=\"en-US\"> key focus will be embedding <\/span><span lang=\"en-US\">microarousals<\/span><span lang=\"en-US\"> within both sleep\u2019s electrical rhythms and sleep-related vasomotor and glymphatic activities, revealing <\/span><span lang=\"en-US\">the microarousals<\/span><span lang=\"en-US\"> as boosters for the interplay across physiology of sleep.<\/span><\/span><\/span><\/span><\/p>\n<p><span style=\"color: #2e2e2e;\"><span style=\"font-family: Liberation Serif, serif;\"><span style=\"font-size: x-large;\"><span style=\"color: #1c1c1c;\"><span lang=\"en-US\">Surprisingly, microarousals in humans are scored when there is an <strong>EEG frequency shift<\/strong> (changes in brain waves) either alone or accompanied by increases in heart rate and\/or muscle tone, according to the scientists. <\/span><\/span><span lang=\"en-US\">The<\/span><span lang=\"en-US\">y<\/span><span lang=\"en-US\"> add<\/span>\u00a0that\u00a0<span lang=\"en-US\">i<\/span><span lang=\"en-US\">n the human <\/span><span lang=\"en-US\">phase of REM<\/span><span lang=\"en-US\">\u00a0sleep, a <\/span><span lang=\"en-US\">microarousal<\/span><span lang=\"en-US\"> is scored once brain desynchronization coincides with electromyogram <strong>(EMG) activity. <\/strong><\/span><strong><span lang=\"en-US\">The latter<\/span><span lang=\"en-US\"> is <\/span><span lang=\"en-US\">widely <\/span><span lang=\"en-US\">used <\/span><span lang=\"en-US\">in medicine <\/span><\/strong><span lang=\"en-US\"><strong>to check muscle work as well as the transmission of impulses in nerves<\/strong>.<\/span><\/span><\/span><\/span><\/p>\n<h2>A neurotransmitter for going back?<\/h2>\n<p><span style=\"color: #2e2e2e;\"><span style=\"font-family: Liberation Serif, serif;\"><span style=\"font-size: x-large;\"><span lang=\"en-US\">Simplifying it means the key is the timely noradrenaline <\/span><span lang=\"en-US\">transmitter<\/span><span lang=\"en-US\"> fluctuations during healthy sleep, causing a brief <\/span><span lang=\"en-US\">wake-like state<\/span><span lang=\"en-US\">. <\/span><span lang=\"en-US\">T<\/span><span lang=\"en-US\">he booster <\/span><span lang=\"en-US\">may <\/span><span lang=\"en-US\">signal <\/span><span lang=\"en-US\">a <\/span><span lang=\"en-US\">shift in the frequencies of brain waves measured with EEG. <\/span><span lang=\"en-US\">However, the shift may also appear without microarousal <\/span><span lang=\"en-US\">as the heart rhythm can accelerate in a graded manner even without brief <\/span><span lang=\"en-US\">wake-like,<\/span><span lang=\"en-US\"> and then the lighter <\/span><span lang=\"en-US\">change<\/span><span lang=\"en-US\"> in EEG <\/span><span lang=\"en-US\">is c<\/span><span lang=\"en-US\">a<\/span><span lang=\"en-US\">ught<\/span><span lang=\"en-US\">. <\/span><span lang=\"en-US\">At the same time, as claim scientists, there are phasic EEG events that do not correspond to an EEG activation, yet they are related to an arousal process. That example is, as stated by the scientists, <\/span><span lang=\"en-US\">\u00a0<\/span><span lang=\"en-US\"><strong>the K-complex. In human sleep EEG, it is a singular, large, slow wave with a biphasic waveform lasting 0.5\u20131 s, which can appear without apparent cause but also in response to sensory stimulation<\/strong>. It is accompanied by heart rate increases. But, in general, microarousals are the strongest <\/span><span lang=\"en-US\">among other <\/span><span lang=\"en-US\">waking-like<\/span><span lang=\"en-US\"> processes.<\/span><\/span><\/span><\/span><\/p>\n<p><span style=\"color: #2e2e2e;\"><span style=\"font-family: Liberation Serif, serif;\"><span style=\"font-size: x-large;\"><span lang=\"en-US\">B<\/span><span lang=\"en-US\">rief <\/span><span lang=\"en-US\">wakes<\/span><span lang=\"en-US\"> are not the same as fragmented sleep. However, the frequency of their occurrence may differ by age and sex. The highest ratio has been observed in adult men. Along with aging, the number of microarousals may increase by 1,5 fold. <\/span><span lang=\"en-US\">The scientists emphasize that deviation from these mean values is diagnostically valuable in diverse sleep disorders. <\/span><\/span><\/span><\/span><\/p>\n<p>&nbsp;<\/p>\n<p lang=\"en-US\">\n","protected":false},"excerpt":{"rendered":"<p>By Marta Kobla\u0144ska, February 21, 2025 Photo: This model suggests that the physiological processes influenced by fluctuations in norepinephrine (NA) during NREM sleep\u2014particularly those related to memory consolidation and glymphatic clearance\u2014function best when these fluctuations occur approximately every 50 seconds. Authors: Anita L\u00fcthi, Maiken Nedergaard. Sleeping is a kind of disengagement from the environment to [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"advanced_seo_description":"","jetpack_seo_html_title":"","jetpack_seo_noindex":false,"_jetpack_memberships_contains_paid_content":false,"footnotes":""},"categories":[10,1,6],"tags":[],"class_list":["post-604","post","type-post","status-publish","format-standard","hentry","category-health-security-in-a-nutshell","category-healthmedical-security","category-medicine-in-a-nutshell"],"jetpack_featured_media_url":"","jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/evolutionandsecurity.com\/index.php?rest_route=\/wp\/v2\/posts\/604","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/evolutionandsecurity.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/evolutionandsecurity.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/evolutionandsecurity.com\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/evolutionandsecurity.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=604"}],"version-history":[{"count":21,"href":"https:\/\/evolutionandsecurity.com\/index.php?rest_route=\/wp\/v2\/posts\/604\/revisions"}],"predecessor-version":[{"id":1710,"href":"https:\/\/evolutionandsecurity.com\/index.php?rest_route=\/wp\/v2\/posts\/604\/revisions\/1710"}],"wp:attachment":[{"href":"https:\/\/evolutionandsecurity.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=604"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/evolutionandsecurity.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=604"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/evolutionandsecurity.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=604"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}