Over more than a century of research has established the fact that sleep benefits the retention of memory. In this review we aim to comprehensively cover the field of "sleep and memory" research by providing a historical perspective on concepts and a discussion of more recent key findings. Whereas initial theories posed a passive role for sleep enhancing memories by protecting them from interfering stimuli, current theories highlight an active role for sleep in which memories undergo a process of system consolidation during sleep. Whereas older research concentrated on the role of rapid-eye-movement (REM) sleep, recent work has revealed the importance of slow-wave sleep (SWS) for memory consolidation and also enlightened some of the underlying electrophysiological, neurochemical, and genetic mechanisms, as well as developmental aspects in these processes. Specifically, newer findings characterize sleep as a brain state optimizing memory consolidation, in opposition to the waking brain being optimized for encoding of memories. Consolidation originates from reactivation of recently encoded neuronal memory representations, which occur during SWS and transform respective representations for integration into long-term memory. Ensuing REM sleep may stabilize transformed memories. While elaborated with respect to hippocampus-dependent memories, the concept of an active redistribution of memory representations from networks serving as temporary store into long-term stores might hold also for non-hippocampus-dependent memory, and even for nonneuronal, i.e., immunological memories, giving rise to the idea that the offline consolidation of memory during sleep represents a principle of long-term memory formation established in quite different physiological systems.

https://www.zora.uzh.ch/id/eprint/77770/1/physiol_rev_93.pdf

About sleep's role in memory

Management of postoperative pain: A clinical practice guideline from the american pain society, the american society of regional anesthesia and pain medicine, and the american society of anesthesiologists' committee on regional anesthesia, executive committee, and administrative council.

Progress Toward In Vivo Use of siRNAs-II

http://michiganbraincoretherapy.com/storage/Scientific%20Research%20SOUTAR/KnyazevDelta.pdf

EEG delta oscillations as a correlate of basic homeostatic and motivational processes.

Sleep is vital to cognitive performance, productivity, health and well-being. Earlier theories of sleep presumed that it occurred at the level of the whole organism and that it was governed by central control mechanisms. However, evidence now indicates that sleep might be regulated at a more local level in the brain: it seems to be a fundamental property of neuronal networks and is dependent on prior activity in each network. Such local-network sleep might be initiated by metabolically driven changes in the production of sleep-regulatory substances. We discuss a mathematical model which illustrates that the sleep-like states of individual cortical columns can be synchronized through humoral and electrical connections, and that whole-organism sleep occurs as an emergent property of local-network interactions.

/pdf/sleep-as-a-fundamental-property-of-neuronal-assemblies-3m231jqk7p.pdf

Sleep as a fundamental property of neuronal assemblies

Background: In a controlled and double-blind study, the authors tested the hypothesis that preoperative insertion of intradermal needles at acupoints 2.5 cm from the spinal vertebrae (bladder meridian) provide satisfactory postoperative analgesia. Methods: The authors enrolled patients scheduled for elective upper and lower abdominal surgery. Before anesthesia, patients undergoing each type of surgery were randomly assigned to one of two groups: acupuncture (n 5 50 and n 5 39 for upper and lower abdominal surgery, respectively) or control (n 5 48 and n 5 38 for upper and lower abdominal surgery, respectively). In the acupuncture group, intradermal needles were inserted to the left and right of bladder meridian 18 ‐24 and 20 ‐26 in upper and lower abdominal surgery before induction of anesthesia, respectively. Postoperative analgesia was maintained with epidural morphine and bolus doses of intravenous morphine. Consumption of intravenous morphine was recorded. Incisional pain at rest and during coughing and deep visceral pain were recorded during recovery and for 4 days thereafter on a four-point verbal rating scale. We also evaluated time-dependent changes in plasma concentrations of cortisol and catecholamines. Results: Starting from the recovery room, intradermal acupuncture increased the fraction of patients with good pain relief as compared with the control (P < 0.05). Consumption of supplemental intravenous morphine was reduced 50%, and the incidence of postoperative nausea was reduced 20 ‐30% in the acupuncture patients who had undergone either upper or lower abdominal surgery (P < 0.01). Plasma cortisol and epinephrine concentrations were reduced 30 ‐50% in the acupuncture group during recovery and on the first postoperative day (P < 0.01). Conclusion: Preoperative insertion of intradermal needles reduces postoperative pain, the analgesic requirement, and opioid-related side effects after both upper and lower abdominal surgery. Acupuncture analgesia also reduces the activation of the sympathoadrenal system that normally accompanies surgery. EPIDURAL analgesia or patient-controlled analgesia relieves postoperative pain in most patients undergoing abdominal surgery. However, analgesic drugs are expensive, and opioid analgesics are associated with complications, including drowsiness, pruritus, nausea and vomiting, and respiratory depression. Even a small reduction in the requirement for opioid analgesics is thus likely to be beneficial. Among the potential methods of reducing perioperative pain is acupuncture. 1‐5 In traditional Chinese theory, there is a series of acupoints called viscera-associated points. Among them are points located 2.5 cm from the spinal vertebrae (bladder meridian [BL]). The viscera-associated BL acupoints are mainly located on middle and lower thoracic vertebrae for upper abdominal organs and on lower thoracic to lumbar vertebrae for lower abdominal organs. Stimulation of these points reduces pain induced by visceral dysfunction. Acupuncture to these points may thus alleviate pain after abdominal surgery. However, traditional needle acupuncture cannot easily be performed at these sites because it would interfere with operative maneuvers and require unusual positioning during recovery. An alternative is insertion of fine intradermal needles. These needles are virtually painless; they can be inserted preoperatively and then maintained in position with adhesive tape throughout surgery and for several postoperative days. An excellent objective measure of postoperative pain

https://civtedu.org/uploads/41572/ufiles/webinar/preoperative_intradermal_acupuncture_effect_on_post_opertative_pain_nausea_etc.pdf

Preoperative Intradermal Acupuncture Reduces Postoperative Pain, Nausea and Vomiting, Analgesic Requirement, and Sympathoadrenal Responses

UNLABELLED Anesthesia and surgery induce macrophage aggregation and neutrophil influx, responses that characterize an inflammatory reaction in the distal airway. We thus evaluated the time-dependent expression of genes for proinflammatory cytokines during propofol and isoflurane anesthesia. We studied patients anesthetized with propofol (n = 20) or isoflurane (n = 20). Alveolar macrophages were harvested by bronchoalveolar lavage immediately, 2, 4, and 6 h after induction of anesthesia, and at the end of surgery. RNA was extracted from harvested cells and cDNA was synthesized by reverse transcription. Expression of interleukin-1beta (IL-1beta), IL-6, IL-8, interferon gamma, and tumor necrosis factor-alpha was measured by semiquantitative polymerase chain reaction using beta-actin as an internal standard. We observed two 10-fold increases in gene expression of all proinflammatory cytokines except IL-6. The increases in IL-8 and interferon gamma were 1.5-3 times greater during isoflurane than propofol anesthesia. Expression of the genes for IL-1beta and tumor necrosis factor-alpha was similar with each anesthetic. Our data thus indicate that the pulmonary inflammatory response accompanying anesthesia and surgery is accompanied by the expression of proinflammatory cytokines, and that this expression was in some cases greater during isoflurane than propofol anesthesia. IMPLICATIONS Gene expression of proinflammatory cytokines in alveolar macrophages increased significantly over time. The increases were greater during isoflurane than propofol anesthesia, suggesting that inflammatory responses at transcriptional levels in alveolar macrophages are modulated by the type and duration of anesthesia.

Expression of genes for proinflammatory cytokines in alveolar macrophages during propofol and isoflurane anesthesia.

Tumor necrosis factor α: Activity dependent expression and promotion of cortical column sleep in rats

State-specific asymmetries in EEG slow wave activity induced by local application of TNFα

STUDY OBJECTIVES To investigate the hypothesis that interleukin (IL)-1beta is involved in mediating localized electroencephalogram synchronization. DESIGN We evaluated bilateral cortical electroencephalograms after unilateral local application of IL-1beta onto the somatosensory cortex of rats. Furthermore, we investigated the effects of unilateral application of an IL-1beta inhibitor, the IL-1 soluble receptor, on spontaneous sleep and sleep rebound after sleep deprivation. SETTING University research laboratory. INTERVENTIONS N/A. PARTICIPANTS Rats. MEASUREMENTS AND RESULTS Neither dose of IL-1beta or the IL-1 soluble receptor affected the duration of non-rapid eye movement sleep or rapid eye movement sleep. Unilateral application of IL-1beta induced state- and frequency-dependent electroencephalogram asymmetries. During non-rapid eye movement sleep, but not during other states, electroencephalographic slow-wave activity was greater on the side that received IL-1beta (10- and 50-ng doses). Electroencephalographic power in the higher frequencies was not affected by IL-1beta in any state. Unilateral application of the IL-1 soluble receptor (0.1, 1.0 and 5.0 microg) had no effect on the spontaneous sleep electroencephalogram. In contrast, unilateral application of the IL-1 soluble receptor (5.0 microg) attenuated sleep deprivation-enhanced electroencephalographic slow-wave power ipsilaterally during non-rapid eye movement sleep. CONCLUSIONS Results suggest that IL-1beta can induce state-dependent localized increases of electroencephalographic delta wave power, suggesting an enhancement of sleep intensity within the cortex.

Tadanobu Yasuda

Papers

Preoperative Intradermal Acupuncture Reduces Postoperative Pain, Nausea and Vomiting, Analgesic Requirement, and Sympathoadrenal Responses

Expression of genes for proinflammatory cytokines in alveolar macrophages during propofol and isoflurane anesthesia.

Tumor necrosis factor α: Activity dependent expression and promotion of cortical column sleep in rats

State-specific asymmetries in EEG slow wave activity induced by local application of TNFα

Interleukin-1β has a Role in Cerebral Cortical State-Dependent Electroencephalographic Slow-Wave Activity