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  Subjects -> PSYCHOLOGY (Total: 983 journals)
Showing 601 - 174 of 174 Journals sorted by number of followers
Nature Human Behaviour     Hybrid Journal   (Followers: 54)
Annual Review of Organizational Psychology and Organizational Behavior     Full-text available via subscription   (Followers: 50)
American Journal of Applied Psychology     Open Access   (Followers: 50)
Frontiers in Behavioral Neuroscience     Open Access   (Followers: 30)
Violence and Gender     Full-text available via subscription   (Followers: 22)
Counseling Psychology and Psychotherapy     Open Access   (Followers: 20)
Behavior Analysis in Practice     Full-text available via subscription   (Followers: 19)
Sport, Exercise, and Performance Psychology     Full-text available via subscription   (Followers: 15)
Current Opinion in Psychology     Hybrid Journal   (Followers: 15)
Journal of Social and Political Psychology     Open Access   (Followers: 14)
Current Addiction Reports     Hybrid Journal   (Followers: 14)
Clinical Practice in Pediatric Psychology     Full-text available via subscription   (Followers: 14)
Review Journal of Autism and Developmental Disorders     Hybrid Journal   (Followers: 14)
Case Studies in Sport and Exercise Psychology     Hybrid Journal   (Followers: 13)
Journal of Gender-Based Violence     Hybrid Journal   (Followers: 13)
Glossa Psycholinguistics     Open Access   (Followers: 13)
Journal of Music Therapy     Hybrid Journal   (Followers: 13)
Autism's Own     Open Access   (Followers: 12)
Psychology of Sexual Orientation and Gender Diversity     Full-text available via subscription   (Followers: 12)
Journal of Experimental Psychology : Animal Learning and Cognition     Full-text available via subscription   (Followers: 11)
Health Psychology Open     Open Access   (Followers: 11)
Clinical Psychology and Special Education     Open Access   (Followers: 10)
Current Opinion in Behavioral Sciences     Hybrid Journal   (Followers: 10)
Couple and Family Psychology : Research and Practice     Full-text available via subscription   (Followers: 10)
Journal of Psychosocial Rehabilitation and Mental Health     Hybrid Journal   (Followers: 10)
Addictive Behaviors Reports     Open Access   (Followers: 8)
Behavior Analysis: Research and Practice     Full-text available via subscription   (Followers: 8)
International Journal of Yoga : Philosophy, Psychology and Parapsychology     Open Access   (Followers: 8)
Evolutionary Behavioral Sciences     Full-text available via subscription   (Followers: 7)
Psychology of Consciousness : Theory, Research, and Practice     Full-text available via subscription   (Followers: 7)
Music Therapy Perspectives     Hybrid Journal   (Followers: 7)
Asian American Journal of Psychology     Full-text available via subscription   (Followers: 7)
Decision     Full-text available via subscription   (Followers: 6)
Evolutionary Psychological Science     Hybrid Journal   (Followers: 6)
Behavior Analyst     Hybrid Journal   (Followers: 6)
Contemporary School Psychology     Hybrid Journal   (Followers: 6)
Creativity. Theories ? Research ? Applications     Open Access   (Followers: 6)
Qualitative Psychology     Full-text available via subscription   (Followers: 6)
Psychomusicology : Music, Mind, and Brain     Full-text available via subscription   (Followers: 6)
Review of Behavioral Economics     Full-text available via subscription   (Followers: 6)
Porn Studies     Hybrid Journal   (Followers: 6)
Internet Interventions : The application of information technology in mental and behavioural health     Open Access   (Followers: 6)
Neurology, Neuropsychiatry, Psychosomatics     Open Access   (Followers: 6)
Journal of Social, Behavioral, and Health Sciences     Open Access   (Followers: 5)
Revista Científica Arbitrada de la Fundación MenteClara     Open Access   (Followers: 5)
European Journal of Investigation in Health, Psychology and Education     Open Access   (Followers: 5)
Journal of Behavioral Addictions     Open Access   (Followers: 5)
OA Autism     Open Access   (Followers: 5)
Journal of Individual Psychology     Full-text available via subscription   (Followers: 5)
Journal of Cognitive Historiography     Full-text available via subscription   (Followers: 5)
Counselling and Values     Hybrid Journal   (Followers: 5)
Cognitive Research : Principles and Implications     Open Access   (Followers: 5)
Archives of Scientific Psychology     Open Access   (Followers: 5)
Drama Therapy Review     Hybrid Journal   (Followers: 4)
SUCHT - Zeitschrift für Wissenschaft und Praxis / Journal of Addiction Research and Practice     Hybrid Journal   (Followers: 4)
International Journal of Educational and Psychological Researches     Open Access   (Followers: 4)
Policy Insights from the Behavioral and Brain Sciences     Full-text available via subscription   (Followers: 4)
Psyke & Logos     Open Access   (Followers: 4)
Voices : A World Forum for Music Therapy     Open Access   (Followers: 4)
African Journal of Cross-Cultural Psychology and Sport Facilitation     Full-text available via subscription   (Followers: 4)
Cultural-Historical Psychology     Open Access   (Followers: 4)
Current Behavioral Neuroscience Reports     Hybrid Journal   (Followers: 4)
Psychology and Law     Open Access   (Followers: 3)
Social Psychology and Society     Open Access   (Followers: 3)
Spirituality in Clinical Practice     Full-text available via subscription   (Followers: 3)
Phenomenology and Mind     Open Access   (Followers: 3)
Inquiry : Critical Thinking Across the Disciplines     Full-text available via subscription   (Followers: 2)
Nigerian Journal of Guidance and Counselling     Full-text available via subscription   (Followers: 2)
Language and Text     Open Access   (Followers: 2)
Research in Psychology and Behavioral Sciences     Open Access   (Followers: 2)
European Journal of Behavior Analysis     Hybrid Journal   (Followers: 2)
Sexual Offending : Theory, Research, and Prevention     Open Access   (Followers: 2)
Lebenswelt : Aesthetics and philosophy of experience     Open Access   (Followers: 2)
Journal of Dynamic Decision Making     Open Access   (Followers: 2)
Multisensory Research     Hybrid Journal   (Followers: 2)
Zeitschrift für Neuropsychologie     Hybrid Journal   (Followers: 2)
Zeitschrift für Psychiatrie, Psychologie und Psychotherapie     Hybrid Journal   (Followers: 2)
Couple and Family Psychoanalysis     Full-text available via subscription   (Followers: 2)
Social Action : The Journal for Social Action in Counseling and Psychology     Free   (Followers: 2)
Phenomenology & Practice     Open Access   (Followers: 2)
Social Inclusion     Open Access   (Followers: 2)
Journal of Language Aggression and Conflict     Hybrid Journal   (Followers: 2)
Journal of Amateur Sport     Open Access   (Followers: 2)
Journal of Psychology in Africa     Full-text available via subscription   (Followers: 1)
Brain Informatics     Open Access   (Followers: 1)
Russian Psychological Journal     Open Access   (Followers: 1)
Psychological Science and Education     Open Access   (Followers: 1)
Undecidable Unconscious : A Journal of Deconstruction and Psychoanalysis     Full-text available via subscription   (Followers: 1)
Jurnal Psikologi Pendidikan dan Konseling : Jurnal Kajian Psikologi Pendidikan dan Bimbingan Konseling     Open Access   (Followers: 1)
Acta de Investigación Psicológica     Open Access   (Followers: 1)
Epiphany     Open Access   (Followers: 1)
Psychosomatic Medicine and General Practice     Open Access   (Followers: 1)
Journal of Mind and Medical Sciences     Open Access   (Followers: 1)
Psychological Science and Education psyedu.ru     Open Access   (Followers: 1)
International Review of Social Psychology / Revue Internationale de Psychologie Sociale     Open Access   (Followers: 1)
Canadian Journal of Art Therapy : Research, Practice, and Issues     Hybrid Journal   (Followers: 1)
Zeitschrift für Kinder- und Jugendpsychiatrie und Psychotherapie     Hybrid Journal   (Followers: 1)
Zeitschrift für Pädagogische Psychologie     Hybrid Journal   (Followers: 1)
Neuropsychoanalysis : An Interdisciplinary Journal for Psychoanalysis and the Neurosciences     Hybrid Journal   (Followers: 1)
Voices : The Art and Science of Psychotherapy     Full-text available via subscription   (Followers: 1)
Activités     Open Access   (Followers: 1)
Tempo Psicanalitico     Open Access   (Followers: 1)
Journal of Educational, Cultural and Psychological Studies     Open Access   (Followers: 1)
Quantitative Methods for Psychology     Open Access   (Followers: 1)
FLEKS : Scandinavian Journal of Intercultural Theory and Practice     Open Access   (Followers: 1)
Canadian Art Therapy Association     Hybrid Journal   (Followers: 1)
Journal of Numerical Cognition     Open Access   (Followers: 1)
Wawasan     Open Access   (Followers: 1)
Zeitschrift für Gerontopsychologie und -psychiatrie     Full-text available via subscription   (Followers: 1)
Psicologia e Saber Social     Open Access   (Followers: 1)
Pragmatic Case Studies in Psychotherapy     Open Access   (Followers: 1)
Behavioral Development Bulletin     Full-text available via subscription   (Followers: 1)
Journal of Addiction & Prevention     Open Access  
Revista de Estudios e Investigación en Psicología y Educación     Open Access  
Persona Studies     Open Access  
Indigenous : Jurnal Ilmiah Psikologi     Open Access  
Intuisi : Jurnal Psikologi Ilmiah     Open Access  
Setting     Full-text available via subscription  
Revista de Psicologia     Open Access  
Behaviormetrika     Hybrid Journal  
European Yearbook of the History of Psychology     Full-text available via subscription  
Interacciones. Revista de Avances en Psicología     Open Access  
Psicologia     Open Access  
Journal für Psychoanalyse     Open Access  
Siglo Cero. Revista Española sobre Discapacidad Intelectual     Open Access  
Miscelánea Comillas. Revista de Ciencias Humanas y Sociales     Open Access  
New School Psychology Bulletin     Open Access  
TESTFÓRUM     Open Access  
S : Journal of the Circle for Lacanian Ideology Critique     Open Access  
International Journal of Psychoanalysis and Education     Open Access  
Quaderns de Psicologia     Open Access  
Satir International Journal     Open Access  
Mudanças - Psicologia da Saúde     Open Access  
Journal of Creating Value     Full-text available via subscription  
Tajdida : Jurnal Pemikiran dan Gerakan Muhammadiyah     Open Access  
Estudos Interdisciplinares em Psicologia     Open Access  
Psychologie du Travail et des Organisations     Hybrid Journal  
Cendekia : Jurnal Kependidikan dan Kemasyarakatan     Open Access  
Visnyk of NTUU - Philosophy. Psychology. Pedagogics     Open Access  
Revista Costarricense de Psicología     Open Access  
Informes Psicológicos     Open Access  
Jurnal Psikologi     Open Access  
Zeitschrift für Differentielle und Diagnostische Psychologie     Full-text available via subscription  
Klart språk i Norden     Open Access  
Revista Pequén     Open Access  
Pensando Psicología     Open Access  
Ciencias Psicológicas     Open Access  
Revista de Cultura Teológica     Open Access  
Journal of Modern Foreign Psychology     Open Access  
Experimental Psychology (Russia)     Open Access  
Elpis - Czasopismo Teologiczne Katedry Teologii Prawosławnej Uniwersytetu w Białymstoku     Open Access  
International Journal of Comparative Psychology     Open Access  
Гуманітарний вісник Запорізької державної інженерної академії     Open Access  
Revista Latinoamericana de Psicología     Open Access  
Cogent Psychology     Open Access  
Ajayu Órgano de Difusión Científica del Departamento de Psicología UCBSP     Open Access  
Psicologia     Open Access  
Análise Psicológica     Open Access  
Rivista Internazionale di Filosofia e Psicologia     Open Access  
Facta Universitatis, Series : Philosophy, Sociology, Psychology and History     Open Access  
Universal Journal of Psychology     Open Access  
Revista Internacional de Psicologia     Open Access  
Terapia familiare     Full-text available via subscription  
Studi Junghiani     Full-text available via subscription  
Ruolo Terapeutico (IL)     Full-text available via subscription  
Rivista Sperimentale di Freniatria     Full-text available via subscription  
Rivista di Psicoterapia Relazionale     Full-text available via subscription  
Ricerche di psicologia     Full-text available via subscription  
Ricerca Psicoanalitica : Journal of the Relationship in Psychoanalysis     Open Access  
Quaderni di Gestalt     Full-text available via subscription  
Psicoterapia e Scienze Umane     Full-text available via subscription  
Psicologia di Comunità. Gruppi, ricerca-azione, modelli formativi     Full-text available via subscription  
Psicologia della salute     Full-text available via subscription  
Psicobiettivo     Full-text available via subscription  
Psicoanalisi     Full-text available via subscription  
Ipnosi     Full-text available via subscription  
Interazioni     Full-text available via subscription  
Gruppi     Full-text available via subscription  
Forum : Journal of the International Association of Group Psychoterapy     Full-text available via subscription  
Educazione sentimentale     Full-text available via subscription  
Revista Wímb Lu     Open Access  
International Perspectives in Psychology : Research, Practice, Consultation     Full-text available via subscription  
Lernen und Lernstörungen     Hybrid Journal  
Inkanyiso : Journal of Humanities and Social Sciences     Open Access  
Online Readings in Psychology and Culture     Open Access  
Winnicott e-prints     Open Access  
Trivium : Estudos Interdisciplinares     Open Access  
Temas em Psicologia     Open Access  
Stylus (Rio de Janeiro)     Open Access  
Salud & Sociedad: investigaciones en psicologia de la salud y psicologia social     Open Access  
Revista Psicopedagogia     Open Access  
Revista Psicologia Política     Open Access  
Revista Psicologia e Saúde     Open Access  
Revista Psicologia     Open Access  
Revista Mexicana de Orientación Educativa     Open Access  
Revista do NUFEN     Open Access  
Revista de Etologia     Open Access  
Revista da SPAGESP     Open Access  
Revista da SBPH     Open Access  
Revista da Abordagem Gestáltica     Open Access  

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Clocks & Sleep
Number of Followers: 1  

  This is an Open Access Journal Open Access journal
ISSN (Online) 2624-5175
Published by MDPI Homepage  [84 journals]
  • Clocks & Sleep, Vol. 4, Pages 475-496: Objective Measures of Immediate
           “Energizing” Effect of Light: Studies Review and Data Analysis

    • Authors: Konstantin V. Danilenko
      First page: 475
      Abstract: While the energizing effect of light has been known since the early years of light therapy, its reliable detection using objective measures is still not well-established. This review aims to ascertain the immediate energizing effect of light and determine its best indicators. Sixty-four articles published before July 2022 were included in the review. The articles described 72 (sub-)studies performed in healthy individuals. Fourteen measures were analyzed. The analysis showed that light causes an energizing effect that can be best documented by measuring core (rectal) body temperature: the proportion of the studies revealing increasing, unchanging, and decreasing rectal temperature was 13/6/1. The second most suitable indicator was heart rate (10/22/1), which showed concordant changes with rectal temperature (a trend, seven mutual studies). There is no evidence from the reviewed articles that oxygen consumption, skin conductance, blood pressure, heart rate variability, non-rectal inner temperature (combined digestive, tympanic, and oral), skin temperature, or cortisol levels can provide light effect detection. Four other measures were found to be unsuitable as well but with less certainty due to the low number of studies (≤3): skin blood flow, noradrenaline, salivary alpha-amylase, and thyroid-stimulating hormone levels. On the other hand, light exposure had a noticeable effect on sympathetic nerve activity measured using microneurography; however, this measure can be accepted as a marker only tentatively as it was employed in a single study. The analysis took into account three factors—study limitation in design/analysis, use of light in day- or nighttime, and relative brightness of the light stimulus—that were found to significantly influence some of the analyzed variables. The review indicates that the energizing effect of light in humans can be reliably detected using rectal temperature and heart rate.
      Citation: Clocks & Sleep
      PubDate: 2022-09-26
      DOI: 10.3390/clockssleep4040038
      Issue No: Vol. 4, No. 4 (2022)
  • Clocks & Sleep, Vol. 4, Pages 497-507: The Impact of Missing Data and
           Imputation Methods on the Analysis of 24-Hour Activity Patterns

    • Authors: Lara Weed, Renske Lok, Dwijen Chawra, Jamie Zeitzer
      First page: 497
      Abstract: The purpose of this study is to characterize the impact of the timing and duration of missing actigraphy data on interdaily stability (IS) and intradaily variability (IV) calculation. The performance of three missing data imputation methods (linear interpolation, mean time of day (ToD), and median ToD imputation) for estimating IV and IS was also tested. Week-long actigraphy records with no non-wear or missing timeseries data were masked with zeros or ‘Not a Number’ (NaN) across a range of timings and durations for single and multiple missing data bouts. IV and IS were calculated for true, masked, and imputed (i.e., linear interpolation, mean ToD and, median ToD imputation) timeseries data and used to generate Bland–Alman plots for each condition. Heatmaps were used to analyze the impact of timings and durations of and between bouts. Simulated missing data produced deviations in IV and IS for longer durations, midday crossings, and during similar timing on consecutive days. Median ToD imputation produced the least deviation among the imputation methods. Median ToD imputation is recommended to recapitulate IV and IS under missing data conditions for less than 24 h.
      Citation: Clocks & Sleep
      PubDate: 2022-09-27
      DOI: 10.3390/clockssleep4040039
      Issue No: Vol. 4, No. 4 (2022)
  • Clocks & Sleep, Vol. 4, Pages 508-519: A Social Media Outage Was
           Associated with a Surge in Nomophobia, and the Magnitude of Change in
           Nomophobia during the Outage Was Associated with Baseline Insomnia

    • Authors: Haitham Jahrami, Feten Fekih-Romdhane, Zahra Saif, Nicola Luigi Bragazzi, Seithikurippu R. Pandi-Perumal, Ahmed S. BaHammam, Michael V. Vitiello
      First page: 508
      Abstract: We examined the immediate impact of a social media outage on nomophobia and associated symptoms using a longitudinal cohort design. Data were collected at two timepoints, baseline (T1) and during the social media outage of 4 October 2021 (T2). T1 was collected in August–September 2021 as part of the baseline of an ongoing study. The nomophobia questionnaire (NMP-Q), Generalized Anxiety Disorder-7 scale (GAD-7), and Athens insomnia scale (AIS) were administered to 2706 healthy participants from the general Bahraini population (56% females, mean age 33.57 ± 11.65 years). Approximately one month later, during the social media outage, 306 of the study participants were opportunistically assessed using the NMP-Q. At baseline, we found that nomophobia levels strongly correlated positively with both insomnia (p = 0.001) and anxiety symptoms (p = 0.001). This is the first report to examine the impact of a social media outage on nomophobia. Our findings indicate that symptoms of nomophobia increased significantly during a social media outage. Baseline insomnia scores predicted a surge in the global scores of nomophobia symptoms during a social media outage.
      Citation: Clocks & Sleep
      PubDate: 2022-09-27
      DOI: 10.3390/clockssleep4040040
      Issue No: Vol. 4, No. 4 (2022)
  • Clocks & Sleep, Vol. 4, Pages 520-534: Sleep Habits in Pairs of Japanese
           High School Students and Their Mothers in Summer and Autumn

    • Authors: Koh Mizuno, Kazue Okamoto-Mizuno, Akiko Maeda
      First page: 520
      Abstract: This study aimed to examine the sleep habits in pairs of Japanese high school students and their mothers in the summer and autumn. Nineteen pairs of high school students and their mothers participated in this study. Wrist actigraphy, subjective sleep evaluations, and bedroom environmental measurements (temperature, humidity, and light) were performed for a duration of one week. The results of a split-plot analysis of variance revealed no significant difference in the actigraphically evaluated time spent in bed (TIB) between the seasons and between the mothers and students. The TIB was approximately 6 h on weekdays, and significantly lengthened to approximately 7 h on weekends (p < 0.05). The average sleep efficiency values recorded were higher than 90%. The mothers showed significantly advanced sleep phases compared to those of the students (p < 0.05). In addition, the waking time on Monday morning was significantly correlated between the mothers and students in the summer and autumn (p < 0.05). A perceived sleep loss “almost every day” or “several times per week” was reported by approximately half of the mothers and students in each season. The students occasionally fell into nocturnal sleep with the room light turned on. These results suggest that sleep hygiene education considering life habit characteristics is required to ensure sufficient sleep time.
      Citation: Clocks & Sleep
      PubDate: 2022-09-28
      DOI: 10.3390/clockssleep4040041
      Issue No: Vol. 4, No. 4 (2022)
  • Clocks & Sleep, Vol. 4, Pages 321-331: Adipokines in Sleep Disturbance and
           Metabolic Dysfunction: Insights from Network Analysis

    • Authors: Zhikui Wei, You Chen, Raghu P. Upender
      First page: 321
      Abstract: Adipokines are a growing group of secreted proteins that play important roles in obesity, sleep disturbance, and metabolic derangements. Due to the complex interplay between adipokines, sleep, and metabolic regulation, an integrated approach is required to better understand the significance of adipokines in these processes. In the present study, we created and analyzed a network of six adipokines and their molecular partners involved in sleep disturbance and metabolic dysregulation. This network represents information flow from regulatory factors, adipokines, and physiologic pathways to disease processes in metabolic dysfunction. Analyses using network metrics revealed that obesity and obstructive sleep apnea were major drivers for the sleep associated metabolic dysregulation. Two adipokines, leptin and adiponectin, were found to have higher degrees than other adipokines, indicating their central roles in the network. These adipokines signal through major metabolic pathways such as insulin signaling, inflammation, food intake, and energy expenditure, and exert their functions in cardiovascular, reproductive, and autoimmune diseases. Leptin, AMP activated protein kinase (AMPK), and fatty acid oxidation were found to have global influence in the network and represent potentially important interventional targets for metabolic and sleep disorders. These findings underscore the great potential of using network based approaches to identify new insights and pharmaceutical targets in metabolic and sleep disorders.
      Citation: Clocks & Sleep
      PubDate: 2022-06-22
      DOI: 10.3390/clockssleep4030027
      Issue No: Vol. 4, No. 3 (2022)
  • Clocks & Sleep, Vol. 4, Pages 332-345: Noradrenergic Signaling in
           Astrocytes Influences Mammalian Sleep Homeostasis

    • Authors: Ashley M. Ingiosi, Marcos G. Frank
      First page: 332
      Abstract: Astrocytes influence sleep expression and regulation, but the cellular signaling pathways involved in these processes are poorly defined. We proposed that astrocytes detect and integrate a neuronal signal that accumulates during wakefulness, thereby leading to increased sleep drive. Noradrenaline (NA) satisfies several criteria for a waking signal integrated by astrocytes. We therefore investigated the role of NA signaling in astrocytes in mammalian sleep. We conditionally knocked out (cKO) β2-adrenergic receptors (β2-AR) selectively in astrocytes in mice and recorded electroencephalographic and electromyographic activity under baseline conditions and in response to sleep deprivation (SDep). cKO of astroglial β2-ARs increased active phase siesta duration under baseline conditions and reduced homeostatic compensatory changes in sleep consolidation and non-rapid eye movement slow-wave activity (SWA) after SDep. Overall, astroglial NA β2-ARs influence mammalian sleep homeostasis in a manner consistent with our proposed model of neuronal–astroglial interactions.
      Citation: Clocks & Sleep
      PubDate: 2022-07-07
      DOI: 10.3390/clockssleep4030028
      Issue No: Vol. 4, No. 3 (2022)
  • Clocks & Sleep, Vol. 4, Pages 346-357: Prediction of Dropout in a
           Randomized Controlled Trial of Adjunctive Light Treatment in Patients with
           Non-Seasonal Depression and Evening Chronotype

    • Authors: Joey W.Y. Chan, Shirley Xin Li, Steven Wai Ho Chau, Ngan Yin Chan, Jihui Zhang, Yun Kwok Wing
      First page: 346
      Abstract: The current study examined the possible predictors of dropout during a five-week light treatment (LT) with a gradual advance protocol in 93 patients with unipolar non-seasonal depression and evening chronotypes by comparing their clinical characteristics and performing a logistic regression analysis. Nineteen out of ninety-three (20%) subjects (80% female, 46.5 ± 11.7 years old) dropped out during the 5-week light treatment. Treatment non-adherence (i.e., receiving LT for less than 80% of the prescribed duration) over the first treatment week predicted a five-fold increase in risk of dropout during light therapy (OR: 5.85, CI: 1.41–24.21) after controlling for potential confounders, including age, gender, treatment group, rise time at the baseline, patient expectation, and treatment-emergent adverse events. There is a need to incorporate strategies to enhance treatment adherence and retention in both research and clinical settings. Chinese clinical trial registry (ChiCTR-IOR-15006937).
      Citation: Clocks & Sleep
      PubDate: 2022-07-27
      DOI: 10.3390/clockssleep4030029
      Issue No: Vol. 4, No. 3 (2022)
  • Clocks & Sleep, Vol. 4, Pages 358-373: The Effect of Light Therapy on
           Electroencephalographic Sleep in Sleep and Circadian Rhythm Disorders: A
           Scoping Review

    • Authors: Teha B. Pun, Craig L. Phillips, Nathaniel S. Marshall, Maria Comas, Camilla M. Hoyos, Angela L. D’Rozario, Delwyn J. Bartlett, Wendy Davis, Wenye Hu, Sharon L. Naismith, Sean Cain, Svetlana Postnova, Ron R. Grunstein, Christopher J. Gordon
      First page: 358
      Abstract: Light therapy is used to treat sleep and circadian rhythm disorders, yet there are limited studies on whether light therapy impacts electroencephalographic (EEG) activity during sleep. Therefore, we aimed to provide an overview of research studies that examined the effects of light therapy on sleep macro- and micro-architecture in populations with sleep and circadian rhythm disorders. We searched for randomized controlled trials that used light therapy and included EEG sleep measures using MEDLINE, PubMed, CINAHL, PsycINFO and Cochrane Central Register of Controlled Trials databases. Five articles met the inclusion criteria of patients with either insomnia or delayed sleep–wake phase disorder (DSWPD). These trials reported sleep macro-architecture outcomes using EEG or polysomnography. Three insomnia trials showed no effect of the timing or intensity of light therapy on total sleep time, wake after sleep onset, sleep efficiency and sleep stage duration compared to controls. Only one insomnia trial reported significantly higher sleep efficiency after evening light therapy (>4000 lx between 21:00–23:00 h) compared with afternoon light therapy (>4000 lx between 15:00–17:00 h). In the only DSWPD trial, six multiple sleep latency tests were conducted across the day (09:00 and 19:00 h) and bright light (2500 lx) significantly lengthened sleep latency in the morning (09:00 and 11:00 h) compared to control light (300 lx). None of the five trials reported any sleep micro-architecture measures. Overall, there was limited research about the effect of light therapy on EEG sleep measures, and studies were confined to patients with insomnia and DSWPD only. More research is needed to better understand whether lighting interventions in clinical populations affect sleep macro- and micro-architecture and objective sleep timing and quality.
      Citation: Clocks & Sleep
      PubDate: 2022-08-09
      DOI: 10.3390/clockssleep4030030
      Issue No: Vol. 4, No. 3 (2022)
  • Clocks & Sleep, Vol. 4, Pages 374-380: NREM Parasomnias: Retrospective
           Analysis of Treatment Approaches and Comorbidities

    • Authors: Naina Limbekar, Jonathan Pham, Rohit Budhiraja, Sogol Javaheri, Lawrence J. Epstein, Salma Batool-Anwar, Milena Pavlova
      First page: 374
      Abstract: The aim of this retrospective analysis is to determine the most frequently prescribed medications for the treatment of NREM parasomnias and evaluate reported outcomes. We performed a retrospective chart review of all patients with NREM parasomnia diagnosed within Brigham and Women’s Hospital (BWH) clinics examining the date of diagnosis, date of starting therapy, comorbidities, type of medication prescribed, and the reported change in symptoms or side effects at follow-up visits. From 2012 to 2019, 110 patients (59 females, 51 male) at BWH clinics received a diagnosis of NREM parasomnia, including sleepwalking and night terrors. The mean age was 44. Comorbidities included obstructive sleep apnea (OSA) (46%), periodic limb movement syndrome (PLMS) (13%), insomnia (19%), Restless leg syndrome (RLS) (9%), epilepsy (4%), and REM behavior disorder (RBD) (9%). Initial treatment strategies include behavioral and safety counseling only (34%), pharmacological treatment (29%), treatment of any comorbidity (28%), and combined treatment of any of the above (9%). Improvement was reported with: treatment of OSA (n = 23 52% reported improvement), melatonin (n = 8, improvement reported by 88%.,benzodiazepine (n = 7, improvement reported by 57%). Treating comorbid conditions is a frequent treatment strategy, often associated with symptom improvement. The pharmacologic treatment most commonly included melatonin and benzodiazepines. Comprehensive management should include behavioral and safety recommendations, assessment of comorbid conditions, and individually tailored pharmaceutical treatment.
      Citation: Clocks & Sleep
      PubDate: 2022-08-16
      DOI: 10.3390/clockssleep4030031
      Issue No: Vol. 4, No. 3 (2022)
  • Clocks & Sleep, Vol. 4, Pages 381-386: Time Course of Motor Activity Wake
           Inertia Dissipation According to Age

    • Authors: Lorenzo Tonetti, Miranda Occhionero, Marco Fabbri, Sara Giovagnoli, Martina Grimaldi, Monica Martoni, Vincenzo Natale
      First page: 381
      Abstract: The time course of motor activity sleep inertia (maSI) dissipation was recently investigated through actigraphy in an everyday life condition from middle childhood to late adulthood. Motor activity sleep inertia was dissipated in 70 min, and the sleep inertia phenomenon was more evident in younger participants than in older participants. The aim of the current secondary analysis of previously published data was to examine, within the same sample, the time course of motor activity wake inertia (maWI) dissipation, i.e., the motor pattern in the transition phase from wakefulness to sleep, according to age. To this end, an overall sample of 374 participants (215 females), ranging in age between 9 and 70 years old, was examined. Each participant was asked to wear an actigraph around their non-dominant wrist for one week. The variation in the motor activity pattern of the wake–sleep transition according to age was examined through functional linear modeling (FLM). FLM showed that motor activity wake inertia dissipated around 20 min after bedtime. Moreover, a lower age was significantly associated with greater motor activity within the last two hours of wakefulness and the first twenty minutes after bedtime. Overall, this pattern of results seems to suggest that maWI dissipation is comparable to that of maSI.
      Citation: Clocks & Sleep
      PubDate: 2022-08-30
      DOI: 10.3390/clockssleep4030032
      Issue No: Vol. 4, No. 3 (2022)
  • Clocks & Sleep, Vol. 4, Pages 387-401: Potential Benefits of Daytime Naps
           on Consecutive Days for Motor Adaptation Learning

    • Authors: Yusuke Murata, Masaki Nishida, Atsushi Ichinose, Shutaro Suyama, Sumi Youn, Kohei Shioda
      First page: 387
      Abstract: Daytime napping offers benefits for motor memory learning and is used as a habitual countermeasure to improve daytime functioning. A single nap has been shown to ameliorate motor memory learning, although the effect of consecutive napping on motor memory consolidation remains unclear. This study aimed to explore the effect of daytime napping over multiple days on motor memory learning. Twenty university students were divided into a napping group and no-nap (awake) group. The napping group performed motor adaption tasks before and after napping for three consecutive days, whereas the no-nap group performed the task on a similar time schedule as the napping group. A subsequent retest was conducted one week after the end of the intervention. Significant differences were observed only for speed at 30 degrees to complete the retention task, which was significantly faster in the napping group than in the awake group. No significant consolidation effects over the three consecutive nap intervention periods were confirmed. Due to the limitations of the different experimental environments of the napping and the control group, the current results warrant further investigation to assess whether consecutive napping may benefit motor memory learning, which is specific to speed.
      Citation: Clocks & Sleep
      PubDate: 2022-08-30
      DOI: 10.3390/clockssleep4030033
      Issue No: Vol. 4, No. 3 (2022)
  • Clocks & Sleep, Vol. 4, Pages 402-411: Dreaming and Sleep-Related
           Metacognitions in Patients with Sleep Disorders

    • Authors: Michael Schredl, Claudia Schilling
      First page: 402
      Abstract: Sleep-related metacognitions play a role in the etiology of insomnia and are distressing while falling asleep. Although similar concepts, such as thought suppression, have been studied in the context of dreaming, the relationship between sleep-related metacognitions and more negatively toned dreaming due to stressful pre-sleep experiences has yet to be studied. Overall, 919 patients with various sleep disorders completed the Metacognitions Questionnaire-Insomnia (MCQ-I20), Arousal Disposition Scale (APS), and Pre-Sleep Arousal Scale (PSAS) and kept a sleep diary over seven days eliciting dream recall, nightmare frequency, and the emotional tone of their dreams. The regression analysis showed that the MCQ-I20 (small effect size) and the APS (medium effect size) were associated with nightmare frequency and negatively toned dream emotions. These findings suggest that dysfunctional sleep-related metacognitions that are active prior to sleep are also associated with more negatively toned dreaming and more nightmares—even after controlling for trait arousability. It would be very interesting to study where therapeutic strategies, such as metacognitive therapy explicitly targeting sleep-related metacognition, could also be beneficial with regard to dreams (more positive dreams and fewer nightmares).
      Citation: Clocks & Sleep
      PubDate: 2022-09-01
      DOI: 10.3390/clockssleep4030034
      Issue No: Vol. 4, No. 3 (2022)
  • Clocks & Sleep, Vol. 4, Pages 412-460: 33rd Annual Meeting of the Society
           for Light Treatment and Biological Rhythms (SLTBR), 23–25 June 2022,
           Manchester, UK

    • Authors: Marijke Gordijn
      First page: 412
      Abstract: The 33rd annual meeting of the Society for Light Treatment and Biological Rhythms was held in Manchester in June 2022 [...]
      Citation: Clocks & Sleep
      PubDate: 2022-09-02
      DOI: 10.3390/clockssleep4030035
      Issue No: Vol. 4, No. 3 (2022)
  • Clocks & Sleep, Vol. 4, Pages 458-465: Effects of One Night of Forced
           Wakefulness on Morning Resting Blood Pressure in Humans: The Role of
           Biological Sex and Weight Status

    • Authors: Lieve T. van Egmond, Pei Xue, Elisa M. S. Meth, Maria Ilemosoglou, Joachim Engström, Christian Benedict
      First page: 458
      Abstract: Permanent night shift work is associated with adverse health effects, including elevated blood pressure (BP) and hypertension. Here, we examined the BP response to one night of forced wakefulness in a sitting position in a cohort without night shift work experience. According to a counterbalanced crossover design, 47 young adults with either obesity (N = 22; 10 women) or normal weight (N = 25; 11 women) participated in one night of sleep and one night of forced wakefulness under in-laboratory conditions. Resting ankle and brachial arterial BP were assessed in the morning, i.e., the time of the day when adverse cardiovascular events peak. After forced wakefulness, diastolic and mean arterial BP were ~4 mmHg higher at the ankle site and ~3 mmHg higher at the brachial site than after regular sleep (p < 0.05). The increase in BP following overnight forced wakefulness was more pronounced among men vs. women and more significant for diastolic BP at both sites among participants with normal weight vs. those with obesity. If confirmed in larger cohorts, including 24 h BP monitoring, people with occupations involving night shifts might benefit from regular BP monitoring. Particular attention should be paid to possible sex- and weight-specific effects of night shift work on BP.
      Citation: Clocks & Sleep
      PubDate: 2022-09-14
      DOI: 10.3390/clockssleep4030036
      Issue No: Vol. 4, No. 3 (2022)
  • Clocks & Sleep, Vol. 4, Pages 466-474: Diurnal Preference and Correlates
           of Multidimensional Perfectionism, Type-D Personality, and Big Five
           Personality Traits

    • Authors: Jodie C. Stevenson, Anna Johann, Asha Akram, Sarah Allen, Umair Akram
      First page: 466
      Abstract: This study examined the extent to which the dimensions of the five-factor model, Type-D personality, and multidimensional perfectionism were associated with a diurnal preference in the general population. A sample of (N = 864) individuals completed the measures of diurnal preference, multidimensional perfectionism, Type-D personality, and the Big Five traits. A correlational analysis determined that agreeableness, conscientiousness, emotional stability, organization, and personal standards were independently related to morningness. In contrast, negative affect, social inhibition, Type-D personality, and perfectionistic doubts and concerns, as well as an increased perception of critical parental evaluation, were independently related to eveningness. After accounting for the shared variance amongst the personality traits, only negative affect, conscientiousness, organization, personal standards, and parental perception were significantly associated with diurnal preference. The current outcomes offer further insight into the relationship between personality and diurnal preference. Here, we observed greater reports of adaptive personality traits in relation to morningness, whereas negative affect and perceived parental evaluation and criticism were related to eveningness. As the first study to examine the relationship between Type-D personality, multidimensional perfectionism, and diurnal preference, the current outcomes should be considered preliminary.
      Citation: Clocks & Sleep
      PubDate: 2022-09-14
      DOI: 10.3390/clockssleep4030037
      Issue No: Vol. 4, No. 3 (2022)
  • Clocks & Sleep, Vol. 4, Pages 208-218: Direct Effects of Light on Sleep
           under Ultradian Light-Dark Cycles Depend on Circadian Time and Pulses

    • Authors: Fanny Fuchs, Ludivine Robin-Choteau, Laurence Hugueny, Dominique Ciocca, Patrice Bourgin
      First page: 208
      Abstract: Ultradian light–dark cycles in rodents are a precious tool to study the direct effects of repeated light exposures on sleep, in order to better understand the underlying mechanisms. This study aims to precisely evaluate the effects of light and dark exposures, according to circadian time, on sleep and waking distribution and quality, and to determine if these effects depend on the duration of light and dark pulses. To do this, mice were exposed to 24 h-long ultradian light–dark cycles with different durations of pulses: T2 cycle (1 h of light/1 h of dark) and T7 cycle (3.5 h of light/3.5 h of dark). Exposure to light not only promotes NREM and REM sleep and inhibits wake, but also drastically alters alertness and modifies sleep depth. These effects are modulated by circadian time, appearing especially during early subjective night, and their kinetics is highly dependent on the duration of pulses, suggesting that in the case of pulses of longer duration, the homeostatic process could overtake light direct influence for shaping sleep and waking distribution.
      Citation: Clocks & Sleep
      PubDate: 2022-03-24
      DOI: 10.3390/clockssleep4020019
      Issue No: Vol. 4, No. 2 (2022)
  • Clocks & Sleep, Vol. 4, Pages 219-229: Respiratory Muscle Training in
           Patients with Obstructive Sleep Apnoea: A Systematic Review and

    • Authors: Rodrigo Torres-Castro, Lilian Solis-Navarro, Homero Puppo, Victoria Alcaraz-Serrano, Luis Vasconcello-Castillo, Jordi Vilaró, Roberto Vera-Uribe
      First page: 219
      Abstract: Background: Effective treatments for obstructive sleep apnoea (OSA) include positive pressure, weight loss, oral appliances, surgery, and exercise. Although the involvement of the respiratory muscles in OSA is evident, the effect of training them to improve clinical outcomes is not clear. We aimed to determine the effects of respiratory muscle training in patients with OSA. Methods: A systematic review was conducted in seven databases. Studies that applied respiratory muscle training in OSA patients were reviewed. Two independent reviewers analysed the studies, extracted the data and assessed the quality of evidence. Results: Of the 405 reports returned by the initial search, eight articles reporting on 210 patients were included in the data synthesis. Seven included inspiratory muscle training (IMT), and one included expiratory muscle training (EMT). Regarding IMT, we found significant improvement in Epworth sleepiness scale in −4.45 points (95%CI −7.64 to −1.27 points, p = 0.006), in Pittsburgh sleep quality index of −2.79 points (95%CI −4.19 to −1.39 points, p < 0.0001), and maximum inspiratory pressure of −29.56 cmH2O (95%CI −53.14 to −5.98 cmH2O, p = 0.01). However, the apnoea/hypopnea index and physical capacity did not show changes. We did not perform a meta-analysis of EMT due to insufficient studies. Conclusion: IMT improves sleepiness, sleep quality and inspiratory strength in patients with OSA.
      Citation: Clocks & Sleep
      PubDate: 2022-04-11
      DOI: 10.3390/clockssleep4020020
      Issue No: Vol. 4, No. 2 (2022)
  • Clocks & Sleep, Vol. 4, Pages 230-239: Combining Wake-Up-Back-to-Bed with
           Cognitive Induction Techniques: Does Earlier Sleep Interruption Reduce
           Lucid Dream Induction Rate'

    • Authors: Daniel Erlacher, Vitus Furrer, Matthias Ineichen, John Braillard, Daniel Schmid
      First page: 230
      Abstract: Lucid dreaming offers the chance to investigate dreams from within a dream and by real-time dialogue between experimenters and dreamers during REM sleep. This state of consciousness opens a new experimental venue for dream research. However, laboratory study in this field is limited due to the rarity of lucid dreamers. In a previous study, we were able to induce in 50% of the participants a lucid dream in a single sleep laboratory night by combining a wake-up-back-to-bed (WBTB) sleep routine and a mnemonic method (Mnemonic Induction of Lucid Dreams, MILD). In three experiments, we tried to replicate our earlier findings while we adapted our procedure in shortening (Exp1–3: 4.5 vs. 6 h of uninterrupted sleep in the first half of the night), simplifying (Exp2: time-based wakening vs. REM wakening in the second half of the night), and applying another induction technique (Exp3: reality testing vs. MILD). In the three conditions, four out of 15 (26%), zero out of 20 (0%), and three out of 15 (20%) participants reported a lucid dream. Compared to the original study, the earlier sleep interruption seems to reduce the lucid dream induction rate. Furthermore, without REM awakenings in the morning, lucid dream induction failed, whereas reality testing showed a lower success rate compared to MILD. Further systematic sleep laboratory studies are needed to develop reliable techniques for lucid dream research.
      Citation: Clocks & Sleep
      PubDate: 2022-04-20
      DOI: 10.3390/clockssleep4020021
      Issue No: Vol. 4, No. 2 (2022)
  • Clocks & Sleep, Vol. 4, Pages 240-259: Socioeconomic Position and
           Excessive Daytime Sleepiness: A Systematic Review of Social
           Epidemiological Studies

    • Authors: Imene Bendaoud, Faustin Armel Etindele Sosso
      First page: 240
      Abstract: The objectives of this empirical study are to describe and discuss the current literature available on the relationship between excessive daytime sleepiness (EDS) and the socioeconomic position (SEP) as well as to provide recommendations for consideration of SEP in sleep medicine and biomedical research. Databases Medline/PubMed, Web of Science, Google scholar and Scopus were screened from January 1990 to December 2020 using PRISMA guidelines and 20 articles were included in the final synthesis. Nineteen studies were cross-sectional and one study was longitudinal. Among these studies, 25.00% (n = 5) are focused on children and adolescent and the remaining 75.00% (n = 15) focused on adults and seniors. Ages ranged from 8 to 18 years old for children/adolescent and ranged from 18 to 102 years old for adults. Main SEP measures presented in these studies were education, income, perceived socioeconomic status and employment. The sample size in these studies varied from N = 90 participants to N = 33,865 participants. Overall, a lower educational level, a lower income and full-time employment were associated with EDS. Symptoms of EDS are prevalent in women, especially those with a low income or no job; and children and adolescents with difficult living conditions or working part time reported more sleep disturbances. SEP is already considered as an important determinant for many health outcomes, but if SEP is embedded in the experimental design in psychosomatic research, biomedical research and clinical practice as a constant variable regardless of outcome; it will move forward future investigations.
      Citation: Clocks & Sleep
      PubDate: 2022-05-16
      DOI: 10.3390/clockssleep4020022
      Issue No: Vol. 4, No. 2 (2022)
  • Clocks & Sleep, Vol. 4, Pages 260-276: Long-Term Effect of a Single Dose
           of Caffeine on Sleep, the Sleep EEG and Neuronal Activity in the
           Peduncular Part of the Lateral Hypothalamus under Constant Dark Conditions

    • Authors: Yumeng Wang, Tom Deboer
      First page: 260
      Abstract: Background: Caffeine is a central nervous system stimulant that influences both the sleep–wake cycle and the circadian clock and is known to influence neuronal activity in the lateral hypothalamus, an important area involved in sleep–wake regulation. Light is a strong zeitgeber and it is known to interact with the effect of caffeine on the sleep–wake cycle. We therefore wanted to investigate the long-term effects of a single dose of caffeine under constant dark conditions. Methods: We performed long-term (2 days) electroencephalogram (EEG)/electromyogram recordings combined with multi-unit neuronal activity recordings in the peduncular part of the lateral hypothalamus (PLH) under constant darkness in Brown Norway rats, and investigated the effect of a single caffeine treatment (15 mg/kg) or saline control given 1 h after the onset of the endogenous rest phase. Results: After a reduction in sleep and an increase in waking and activity in the first hours after administration, also on the second recording day after caffeine administration, rapid eye movement (REM) sleep was still reduced. Analysis of the EEG showed that power density in the theta range during waking and REM sleep was increased for at least two days. Neuronal activity in PLH was also increased for two days after the treatment, particularly during non-rapid eye movement sleep. Conclusion: Surprisingly, the data reveal long-term effects of a single dose of caffeine on vigilance states, EEG, and neuronal activity in the PLH. The absence of a light–dark cycle may have enabled the expression of these long-term changes. It therefore may be that caffeine, or its metabolites, have a stronger and longer lasting influence, particularly on the expression of REM sleep, than acknowledged until now.
      Citation: Clocks & Sleep
      PubDate: 2022-05-25
      DOI: 10.3390/clockssleep4020023
      Issue No: Vol. 4, No. 2 (2022)
  • Clocks & Sleep, Vol. 4, Pages 277-286: Effect of Modified
           Yukmijihwang-Tang on Sleep Quality in the Rat

    • Authors: SunYoung Lee, Hun-Soo Lee, Minsook Ye, Min-A Kim, Hwajung Kang, Sung Ja Rhie, Mi Young Lee, In Chul Jung, In-Cheol Kang, Insop Shim
      First page: 277
      Abstract: Many plants have been used in Korean medicine for treating insomnia. However, scientific evidence for their sedative activity has not been fully investigated. Thus, this study was carried out to investigate the sedative effects of the extracts of medicinal plants, including Yukmijihwang-tang and its various modified forms through the 5-HT2c receptor binding assay, and to further confirm its sleep-promoting effects and the underlying neural mechanism in rats utilizing electroencephalography (EEG) analysis. Enzyme-linked immunosorbent assay (ELISA) was used to measure serotonin (5-HT) in the brain. The water extracts of modified Yukmijihwang-tang (YmP) displayed binding affinity to the 5-HT2C receptor (IC50 value of 199.9 µg/mL). YmP (50 mg/kg) administration decreased wake time and increased REM and NREM sleep based on EEG data in rats. Additionally, treatment with YmP significantly increased the 5-HT level in the hypothalamus. In conclusion, the sedative effect of YmP can be attributed to the activation of the central serotonergic systems, as evidenced by the high affinity of binding of the 5-HT2C receptor and increased 5-HT levels in the brain of the rat. This study suggests that YmP can be a new material as a sleep inducer in natural products.
      Citation: Clocks & Sleep
      PubDate: 2022-05-27
      DOI: 10.3390/clockssleep4020024
      Issue No: Vol. 4, No. 2 (2022)
  • Clocks & Sleep, Vol. 4, Pages 287-299: Neuroimaging in the Rare Sleep
           Disorder of Kleine–Levin Syndrome: A Systematic Review

    • Authors: Juan Fernando Ortiz, Jennifer M. Argudo, Mario Yépez, Juan Andrés Moncayo, Hyder Tamton, Alex S. Aguirre, Ghanshyam Patel, Meghdeep Sen, Ayushi Mistry, Ray Yuen, Ahmed Aeissa Garces, Diego Ojeda, Samir Ruxmohan
      First page: 287
      Abstract: Kleine–Levin syndrome (KLS) is characterized by episodes of hypersomnia. Additionally, these patients can present with hyperphagia, hypersexuality, abnormal behavior, and cognitive dysfunction. Functional neuroimaging studies such as fMRI-BOLD, Positron Emission Tomography (PET) or SPECT help us understand the neuropathological bases of different disorders. We conducted a systematic review to investigate the neuroimaging features of KLS patients and their clinical correlations. This systematic review was conducted by following the Meta-Analysis of Observational Studies in Epidemiology (MOOSE) and PRISMA protocol reporting guidelines. We aim to investigate the clinical correlation with neuroimaging among patients with KLS. We included only studies written in the English language in the last 20 years, conducted on humans; 10 studies were included. We excluded systematic reviews, metanalysis, and case reports. We found that there are changes in functional imaging studies during the symptomatic and asymptomatic periods as well as in between episodes in patients with K.L.S. The areas most reported as affected were the hypothalamic and thalamic regions, which showed hypoperfusion and, in a few cases, hyperperfusion; areas such as the frontal, parietal, occipital and the prefrontal cortex all showed alterations in cerebral perfusion. These changes in cerebral blood flow and regions vary according to the imaging (SPECT, PET SCAN, or fMRI) and the task performed while imaging was performed. We encountered conflicting data between studies. Hyper insomnia, the main feature of this disease during the symptomatic periods, was associated with decreased thalamic activity. Other features of K.L.S., such as apathy, hypersexuality, and depersonalization, were also correlated with functional imaging changes. There were also findings that correlated with working memory deficits seen in this stage during the asymptomatic periods. Hyperactivity of the thalamus and hypothalamus were the main features shown during the asymptomatic period. Additionally, functional imaging tends to improve with a longer course of the disease, which suggests that K.L.S. patients outgrow the disease. These findings should caution physicians when analyzing and correlating neuroimaging findings with the disease.
      Citation: Clocks & Sleep
      PubDate: 2022-05-31
      DOI: 10.3390/clockssleep4020025
      Issue No: Vol. 4, No. 2 (2022)
  • Clocks & Sleep, Vol. 4, Pages 300-320: 2021 Annual Meeting of the Swiss
           Society for Sleep Research, Sleep Medicine, and Chronobiology (SSSSC)

    • Authors: Martin Hatzinger
      First page: 300
      Abstract: The 2021 meeting in Solothurn provided evidence-based education to advance the science and clinical practice of sleep medicine and sleep physiology, disseminates cutting-edge sleep and circadian research, promotes the translation of basic science into clinical practice, and fosters the future of the field by allowing young clinicians and researchers to present their findings in talks and on posters [...]
      Citation: Clocks & Sleep
      PubDate: 2022-06-07
      DOI: 10.3390/clockssleep4020026
      Issue No: Vol. 4, No. 2 (2022)
  • Clocks & Sleep, Vol. 4, Pages 8: Acknowledgment to Reviewers of Clocks
           & Sleep in 2021

    • Authors: Clocks & Sleep Editorial Office Clocks & Sleep Editorial Office
      First page: 8
      Abstract: Rigorous peer-reviews are the basis of high-quality academic publishing [...]
      Citation: Clocks & Sleep
      PubDate: 2022-01-27
      DOI: 10.3390/clockssleep4010002
      Issue No: Vol. 4, No. 1 (2022)
  • Clocks & Sleep, Vol. 4, Pages 9-15: Dream Recall/Affect and Cortisol:
           An Exploratory Study

    • Authors: Alexandros S. Triantafyllou, Ioannis Ilias, Nicholas-Tiberio Economou, Athina Pappa, Eftychia Koukkou, Paschalis Steiropoulos
      First page: 9
      Abstract: The effect of cortisol on dreams has been scarcely studied. The aim of this exploratory study was to assess the possible effect of cortisol levels on dream recall/affect, considering, in female subjects, their menstrual cycle phase. Fifteen men and fifteen women were recruited. Saliva samples were used for the detection of cortisol levels. Participants were instructed to provide four saliva samples, during three consecutive days. After awakening, on the second and third day, they were asked whether they could recall the previous night’s dreams and whether these were pleasant or unpleasant. Female subjects followed this procedure twice: firstly, during the luteal phase and, secondly, during the follicular phase of the menstrual cycle. Subjects with higher evening or higher morning cortisol levels tended to show increased dream recall; a non-statistically significant association between morning cortisol levels and positive dream affect was also found. This association acquired statistical significance for salivary morning cortisol levels exceeding the upper normal level of 19.1 nmol/L (OR: 4.444, 95% CI: 1.108–17.830, p-value: 0.039). No connection between menstrual cycle stages and dream recall/affect was detected. In conclusion, cortisol may be a crucial neuromodulator, affecting dream recall and content. Therefore, its effects on sleep and dreams should be further studied.
      Citation: Clocks & Sleep
      PubDate: 2022-01-29
      DOI: 10.3390/clockssleep4010003
      Issue No: Vol. 4, No. 1 (2022)
  • Clocks & Sleep, Vol. 4, Pages 16-22: Cross Sectional Study of the
           Community Self-Reported Risk of Obstructive Sleep Apnoea (OSA) and
           Awareness in Thessaly, Greece

    • Authors: Petros Kassas, Georgios D. Vavougios, Chrissi Hatzoglou, Konstantinos I. Gourgoulianis, Sotirios G. Zarogiannis
      First page: 16
      Abstract: The purpose of this study was to investigate the self-reported risk of obstructive sleep apnea syndrome (OSAS) in the municipality of Thessaly, Greece, and the level of awareness of both the disease and its diagnosis. Inhabitants of Thessaly (254 total; 84 men and 170 women) were studied by means of questionnaires via a telephone-randomized survey. This comprised: (a) the Berlin questionnaire for evaluation of OSAS risk; (b) the evaluation of daytime sleepiness by the Epworth Sleepiness Scale; and (c) demographic and anthropometric data. The percentage of participants at high risk for OSA was 26.77%, and the percentage of people who were at high risk of excessive daytime sleepiness was 10.63%. High risk for OSAS was found to be 3.94%. No significant differences were found between high- and low-risk OSAS participants associated with age, smoking and severity of smoking. Regarding the knowledge of the community about OSAS, the majority of the sample was aware of the entity (64.17%), while fewer had knowledge about the diagnosis (18.50%) and polysomnography (24.80%). The high risk of OSA prevalence and the low awareness of the diagnosis of OSA highlights the need for the development of health promotion programs aiming at increasing the disease awareness in the general population in order to address OSA more effectively.
      Citation: Clocks & Sleep
      PubDate: 2022-02-10
      DOI: 10.3390/clockssleep4010004
      Issue No: Vol. 4, No. 1 (2022)
  • Clocks & Sleep, Vol. 4, Pages 23-36: Working around the Clock: Is a
           Person’s Endogenous Circadian Timing for Optimal Neurobehavioral
           Functioning Inherently Task-Dependent'

    • Authors: Rachael A. Muck, Amanda N. Hudson, Kimberly A. Honn, Shobhan Gaddameedhi, Hans P. A. Van Dongen
      First page: 23
      Abstract: Neurobehavioral task performance is modulated by the circadian and homeostatic processes of sleep/wake regulation. Biomathematical modeling of the temporal dynamics of these processes and their interaction allows for prospective prediction of performance impairment in shift-workers and provides a basis for fatigue risk management in 24/7 operations. It has been reported, however, that the impact of the circadian rhythm—and in particular its timing—is inherently task-dependent, which would have profound implications for our understanding of the temporal dynamics of neurobehavioral functioning and the accuracy of biomathematical model predictions. We investigated this issue in a laboratory study designed to unambiguously dissociate the influences of the circadian and homeostatic processes on neurobehavioral performance, as measured during a constant routine protocol preceded by three days on either a simulated night shift or a simulated day shift schedule. Neurobehavioral functions were measured every 2 h using three functionally distinct assays: a digit symbol substitution test, a psychomotor vigilance test, and the Karolinska Sleepiness Scale. After dissociating the circadian and homeostatic influences and accounting for inter-individual variability, peak circadian performance occurred in the late biological afternoon (in the “wake maintenance zone”) for all three neurobehavioral assays. Our results are incongruent with the idea of inherent task-dependent differences in the endogenous circadian impact on performance. Rather, our results suggest that neurobehavioral functions are under top-down circadian control, consistent with the way they are accounted for in extant biomathematical models.
      Citation: Clocks & Sleep
      PubDate: 2022-02-11
      DOI: 10.3390/clockssleep4010005
      Issue No: Vol. 4, No. 1 (2022)
  • Clocks & Sleep, Vol. 4, Pages 37-51: Depriving Mice of Sleep also
           Deprives of Food

    • Authors: Nina Đukanović, Francesco La Spada, Yann Emmenegger, Guy Niederhäuser, Frédéric Preitner, Paul Franken
      First page: 37
      Abstract: Both sleep-wake behavior and circadian rhythms are tightly coupled to energy metabolism and food intake. Altered feeding times in mice are known to entrain clock gene rhythms in the brain and liver, and sleep-deprived humans tend to eat more and gain weight. Previous observations in mice showing that sleep deprivation (SD) changes clock gene expression might thus relate to altered food intake, and not to the loss of sleep per se. Whether SD affects food intake in the mouse and how this might affect clock gene expression is, however, unknown. We therefore quantified (i) the cortical expression of the clock genes Per1, Per2, Dbp, and Cry1 in mice that had access to food or not during a 6 h SD, and (ii) food intake during baseline, SD, and recovery sleep. We found that food deprivation did not modify the SD-incurred clock gene changes in the cortex. Moreover, we discovered that although food intake during SD did not differ from the baseline, mice lost weight and increased food intake during subsequent recovery. We conclude that SD is associated with food deprivation and that the resulting energy deficit might contribute to the effects of SD that are commonly interpreted as a response to sleep loss.
      Citation: Clocks & Sleep
      PubDate: 2022-02-11
      DOI: 10.3390/clockssleep4010006
      Issue No: Vol. 4, No. 1 (2022)
  • Clocks & Sleep, Vol. 4, Pages 52-65: Hormone Targets for the Treatment of
           Sleep Disorders in Postmenopausal Women with Schizophrenia: A Narrative

    • Authors: Alexandre González-Rodríguez, José Haba-Rubio, Judith Usall, Mentxu Natividad, Virginia Soria, Javier Labad, José A. Monreal
      First page: 52
      Abstract: While the early identification of insomnia in patients with schizophrenia is of clinical relevance, the use of specific compounds to treat insomnia has been studied less in postmenopausal women with schizophrenia. We aimed to explore the effects of melatonin, sex hormones, and raloxifene for the treatment of insomnia in these populations. Although melatonin treatment improved the quality and efficiency of the sleep of patients with schizophrenia, few studies have explored its use in postmenopausal women with schizophrenia. The estrogen and progesterone pathways are dysregulated in major psychiatric disorders, such as in schizophrenia. While, in the context of menopause, a high testosterone-to-estradiol ratio is associated with higher frequencies of depressive symptoms, the effects of estradiol and other sex hormones on sleep disorders in postmenopausal women with schizophrenia has not been sufficiently investigated. Raloxifene, a selective estrogen receptor modulator, has shown positive effects on sleep disorders in postmenopausal women. Future studies should investigate the effectiveness of hormonal compounds on insomnia in postmenopausal women with schizophrenia.
      Citation: Clocks & Sleep
      PubDate: 2022-02-15
      DOI: 10.3390/clockssleep4010007
      Issue No: Vol. 4, No. 1 (2022)
  • Clocks & Sleep, Vol. 4, Pages 66-79: The Importance of Sleep and Circadian
           Rhythms for Vaccination Success and Susceptibility to Viral Infections

    • Authors: Nina C. M. Schmitz, Ysbrand D. van der Werf, Heidi M. Lammers-van der Holst
      First page: 66
      Abstract: Sleep and circadian rhythms are closely involved in the immune system and its regulation. Here, we describe this relationship and provide recommendations regarding the influence of sleep and circadian rhythms on vaccination success. We review studies investigating how viral susceptibility is influenced by changes in immunological parameters as a consequence of sleep deprivation. Short sleep duration and poor sleep efficiency both appear to be strong factors leading to greater vulnerability. In addition, both sleep duration and the time of day of the vaccination seem to be associated with the magnitude of the antibody response after vaccination. Based on these findings, a recommendation would consist of a sleep duration of 7 h or more every night to both reduce the risk of infection and to optimize the efficacy of vaccination with respect to circadian timing. Improving sleep quality and its circadian timing can potentially play a role in preventing infection and in vaccination benefits. In conclusion, sufficient (or longer) sleep duration is important in both reducing susceptibility to infection and increasing antibody response after vaccination.
      Citation: Clocks & Sleep
      PubDate: 2022-02-16
      DOI: 10.3390/clockssleep4010008
      Issue No: Vol. 4, No. 1 (2022)
  • Clocks & Sleep, Vol. 4, Pages 80-87: Measuring Sleep Health Disparities
           with Polysomnography: A Systematic Review of Preliminary Findings

    • Authors: Faustin Armel Etindele Sosso
      First page: 80
      Abstract: Socioeconomic status (SES) has an unrecognized influence on behavioral risk factors as well as public health strategies related to sleep health disparities. In addition to that, objectively measuring SES’ influence on sleep health is challenging. A systematic review of polysomnography (PSG) studies investigating the relation between SES and sleep health disparities is worthy of interest and holds potential for future studies and recommendations. A literature search in databases was conducted following Prisma guidelines. Search strategy identified seven studies fitting within the inclusion criteria. They were all cross-sectional studies with only adults. Except for one study conducted in India, all of these studies took place in western countries. Overall emerging trends are: (1) low SES with its indicators (income, education, occupation and employment) are negatively associated with PSG parameters and (2) environmental factors (outside noise, room temperature and health worries); sex/gender and BMI were the main moderators of the relation between socioeconomic indicators and the variation of sleep recording with PSG. Socioeconomic inequalities in sleep health can be measured objectively. It will be worthy to examine the SES of participants and patients before they undergo PSG investigation. PSG studies should always collect socioeconomic data to discover important connections between SES and PSG. It will be interesting to compare PSG data of people from different SES in longitudinal studies and analyze the intensity of variations through time.
      Citation: Clocks & Sleep
      PubDate: 2022-02-18
      DOI: 10.3390/clockssleep4010009
      Issue No: Vol. 4, No. 1 (2022)
  • Clocks & Sleep, Vol. 4, Pages 88-99: Pre-Sleep Cognitive Arousal Is
           Negatively Associated with Sleep Misperception in Healthy Sleepers during
           Habitual Environmental Noise Exposure: An Actigraphy Study

    • Authors: Rachel L. Sharman, Michael L. Perlis, Célyne H. Bastien, Nicola L. Barclay, Jason G. Ellis, Greg J. Elder
      First page: 88
      Abstract: Specific noises (e.g., traffic or wind turbines) can disrupt sleep and potentially cause a mismatch between subjective sleep and objective sleep (i.e., “sleep misperception”). Some individuals are likely to be more vulnerable than others to noise-related sleep disturbances, potentially as a result of increased pre-sleep cognitive arousal. The aim of the present study was to examine the relationships between pre-sleep cognitive arousal and sleep misperception. Sixteen healthy sleepers participated in this naturalistic, observational study. Three nights of sleep were measured using actigraphy, and each 15-s epoch was classified as sleep or wake. Bedside noise was recorded, and each 15-s segment was classified as containing noise or no noise and matched to actigraphy. Participants completed measures of habitual pre-sleep cognitive and somatic arousal and noise sensitivity. Pre-sleep cognitive and somatic arousal levels were negatively associated with subjective–objective total sleep time discrepancy (p < 0.01). There was an association between sleep/wake and noise presence/absence in the first and last 90 min of sleep (p < 0.001). These results indicate that higher levels of habitual pre-sleep arousal are associated with a greater degree of sleep misperception, and even in healthy sleepers, objective sleep is vulnerable to habitual bedside noise.
      Citation: Clocks & Sleep
      PubDate: 2022-02-24
      DOI: 10.3390/clockssleep4010010
      Issue No: Vol. 4, No. 1 (2022)
  • Clocks & Sleep, Vol. 4, Pages 100-113: Obesity, Sex, Snoring and Severity
           of OSA in a First Nation Community in Saskatchewan, Canada

    • Authors: James A. Dosman, Chandima P. Karunanayake, Mark Fenton, Vivian R. Ramsden, Jeremy Seeseequasis, Robert Skomro, Shelley Kirychuk, Donna C. Rennie, Kathleen McMullin, Brooke P. Russell, Niels Koehncke, Sylvia Abonyi, Malcolm King, Punam Pahwa
      First page: 100
      Abstract: Sleep disorders have been related to body weight, social conditions, and a number of comorbidities. These include high blood pressure and type 2 diabetes, both of which are prevalent in the First Nations communities. We explored relationships between obstructive sleep apnea (OSA) and risk factors including social, environmental, and individual circumstances. An interviewer-administered survey was conducted with adult participants in 2018–2019 in a First Nations community in Saskatchewan, Canada. The survey collected information on demographic variables, individual and contextual determinants of sleep health, and objective clinical measurements. The presence of OSA was defined as an apnea–hypopnea index (AHI) ≥5. Multiple ordinal logistic regression analysis was conducted to examine relationships between the severity of OSA and potential risk factors. In addition to the survey, 233 men and women participated in a Level 3 one-night home sleep test. Of those, 105 (45.1%) participants were reported to have obstructive sleep apnea (AHI ≥ 5). Mild and moderately severe OSA (AHI ≥ 5 to <30) was present in 39.9% and severe OSA (AHI ≥ 30) was identified in 5.2% of participants. Being male, being obese, and snoring loudly were significantly associated with severity of OSA. The severity of OSA in one First Nation appears relatively common and may be related to mainly individual factors such as loud snoring, obesity, and sex.
      Citation: Clocks & Sleep
      PubDate: 2022-02-24
      DOI: 10.3390/clockssleep4010011
      Issue No: Vol. 4, No. 1 (2022)
  • Clocks & Sleep, Vol. 4, Pages 114-128: Circadian and Sleep Modulation of
           Dreaming in Women with Major Depression

    • Authors: Angelina Birchler-Pedross, Sylvia Frey, Christian Cajochen, Sarah L. Chellappa
      First page: 114
      Abstract: Growing evidence indicates an association between reduced dream recall and depressive symptomatology. Here, we tested the prediction that reduced dream recall in individuals experiencing major depressive disorder (MDD) is due to alterations in circadian and sleep processes. Nine young healthy women (20–31 years) and eight young unmedicated women (20–31 years) diagnosed with MDD underwent a 40 h multiple nap protocol with ten alternating cycles of 150 min wake/75 min sleep under a stringently controlled circadian laboratory protocol. After each nap, we assessed dream recall, number of dreams and dream emotional load using the Sleep Mentation Questionnaire. Dream recall and the number of dreams did not significantly differ between groups (pFDR > 0.1). However, there was a significant difference for the dream emotional load (interaction of “Group” vs. “Time”, pFDR = 0.01). Women with MDD had a two-fold higher (negative) emotional load as compared to healthy control women, particularly after naps during the circadian night (between ~22:00 h and ~05:00 h; Tukey–Kramer test, p = 0.009). Furthermore, higher (negative) dream emotional load was associated with impaired mood levels in both groups (R2 = 0.71; p < 0.001). Our findings suggest that the circadian and sleep modulation of dreaming may remain intact in unmedicated young women experiencing MDD.
      Citation: Clocks & Sleep
      PubDate: 2022-02-28
      DOI: 10.3390/clockssleep4010012
      Issue No: Vol. 4, No. 1 (2022)
  • Clocks & Sleep, Vol. 4, Pages 129-144: The Effects of Parental
           Intervention on Sleep Patterns and Electronic Media Exposure in Young

    • Authors: Ofra Flint Bretler, Orna Tzischinsky, Kfir Asraf, Tamar Shochat
      First page: 129
      Abstract: Objective: This study evaluated the effectiveness of a parent-focused intervention aimed at the promotion of healthy sleep patterns and controlled exposure to electronic media (EM) in young adolescents. Participants: The sample included 70 dyads of parents (68 mothers and 2 fathers) and adolescents. Intervention and control groups each consisted of 35 young adolescents with a mean age of 10.7 (0.9) years old. Methods: Three waves of data collection included baseline, post-intervention, and 3 month follow-up. In each wave, adolescents reported habitual electronic media exposure and sleep patterns for a week and wore an actigraph for five nights. Parents in the intervention group participated in a six-session interactive workshop, while parents in the control group received equivalent written information by mail. Results: The intervention led to earlier bedtimes (p < 0.001), increased sleep efficiency (p < 0.01), increased sleep duration (p < 0.001) and reduced video games exposure (p < 0.01). Benefits were maintained at the follow-up. Conclusion: Interventions tailored for parents can create lasting positive changes in sleep patterns and EM exposure in young adolescents.
      Citation: Clocks & Sleep
      PubDate: 2022-03-01
      DOI: 10.3390/clockssleep4010013
      Issue No: Vol. 4, No. 1 (2022)
  • Clocks & Sleep, Vol. 4, Pages 145-159: Sedative–Hypnotic Activity of
           the Water Extracts of Coptidis Rhizoma in Rodents

    • Authors: Hye-Young Joung, Minsook Ye, Miyoung Lee, Yunki Hong, Minji Kim, Kyung Soo Kim, Insop Shim
      First page: 145
      Abstract: Many medicinal plants have been used in Asia for treating a variety of mental diseases, including insomnia and depression. However, their sedative–hypnotic effects and mechanisms have not been clarified yet. Accordingly, the objective of this study was to investigate the sedative–hypnotic effects of water extracts of five medicinal plants: Coptidis Rhizoma, Lycii Fructus, Angelicae sinensis Radix, Bupleuri Radix, and Polygonum multiflorum Thunberg. The binding abilities of five medicinal plant extracts to the GABAA–BZD and 5-HT2C receptors were compared. Their abilities to activate arylalkylamine N-acetyltransferase (AANAT), a melatonin synthesis enzyme, in pineal cells were also determined. Following in vitro tests, the sedative and hypnotic activities of extracts with the highest activities were determined in an animal sleep model. In the binding assay, the water extracts of Coptidis Rhizoma (WCR) showed high binding affinity to the GABAA–BZD and 5-HT2C receptors in a dose-dependent manner. Additionally, WCR increased the AANAT activity up to five times compared with the baseline level. Further animal sleep model experiments showed that WCR potentiated pentobarbital-induced sleep by prolonging the sleep time. It also decreased the sleep onset time in mice. In addition, WCR reduced wake time and increased non-rapid eye movement (NREM) sleep without EEG power density (percentages of δ, θ, and α waves) during NREM sleep in rats. WCR could effectively induce NREM sleep without altering the architectural physiologic profile of sleep. This is the first report of the sedative–hypnotic effect of Coptidis Rhizoma possibly by regulating GABAA and 5-HT2C receptors and by activating AANAT activity.
      Citation: Clocks & Sleep
      PubDate: 2022-03-04
      DOI: 10.3390/clockssleep4010014
      Issue No: Vol. 4, No. 1 (2022)
  • Clocks & Sleep, Vol. 4, Pages 160-171: Sleep Loss, Daytime Sleepiness, and
           Neurobehavioral Performance among Adolescents: A Field Study

    • Authors: Tzischinsky Orna, Barel Efrat
      First page: 160
      Abstract: The current study investigates the impact of sleep loss on neurobehavioral functioning and sleepiness in a natural setting among healthy adolescents. Fifty-nine adolescents (32 females) from grades 7 to 12 (mean age of 16.29 ± 1.86 years) participated in the study. All participants wore the actigraph for a continuous five to seven days, including school and nonschool days. Subjective sleepiness and neurobehavioral performance (using the psychomotor vigilance test and the digit symbol substitution test) were measured three times a day on two school days and one nonschool day. The results presented that sleep loss influenced subjective sleepiness reports, showing higher sleepiness scores following sleep loss than following sufficient night sleep. Neurobehavioral functioning across all measurements was also significantly worse following sleep loss. Furthermore, participants performed worse on weekday morning assessments than on assessments at other times of the day following sleep loss. These findings suggest that sleep loss in natural settings has a significant impact on neurobehavioral performance and subjective sleepiness. Our findings have essential implications for public policy on school schedules.
      Citation: Clocks & Sleep
      PubDate: 2022-03-07
      DOI: 10.3390/clockssleep4010015
      Issue No: Vol. 4, No. 1 (2022)
  • Clocks & Sleep, Vol. 4, Pages 172-184: The Relationship between Acceptance
           and Sleep–Wake Quality before, during, and after the First Italian
           COVID-19 Lockdown

    • Authors: Marco Fabbri, Luca Simione, Monica Martoni, Marco Mirolli
      First page: 172
      Abstract: Several studies have reported that the COVID-19 pandemic has had deleterious effects on sleep quality and mood, but the mechanisms underlying these effects are not clearly understood. Recently, it has been shown that the acceptance component of mindfulness reduces anxiety, and, in turn, lower anxiety improves sleep quality. The purpose of this cross-sectional study was to assess changes in mindfulness traits, sleep–wake quality, and general distress, before, during, and after the first COVID-19 wave, testing the model in which acceptance influences sleep through anxiety in each period. A total of 250 participants were recruited before (Pre-Lockdown group: 69 participants, 29 females, 33.04 ± 12.94 years), during (Lockdown group: 78 participants, 59 females, 29.174 ± 8.50 years), and after (After-Lockdown group: 103 participants, 86 females, 30.29 ± 9.46 years) the first Italian lockdown. In each group, self-report questionnaires, assessing mindfulness facets, distress, and sleep–wake quality, were administered and assessed. The Lockdown group reported lower acceptance and higher depression, while the After-Lockdown group reported lower sleep–wake quality and higher anxiety. The results of the path analysis confirmed that higher acceptance reduced anxiety and higher anxiety decreased sleep–wake quality in all groups. Our results confirm that acceptance influences sleep through the mediating role of anxiety.
      Citation: Clocks & Sleep
      PubDate: 2022-03-07
      DOI: 10.3390/clockssleep4010016
      Issue No: Vol. 4, No. 1 (2022)
  • Clocks & Sleep, Vol. 4, Pages 185-201: Physical Interaction between
           Cyclin-Dependent Kinase 5 (CDK5) and Clock Factors Affects the Circadian
           Rhythmicity in Peripheral Oscillators

    • Authors: Jürgen A. Ripperger, Rohit Chavan, Urs Albrecht, Andrea Brenna
      First page: 185
      Abstract: Circadian rhythms are self-sustained oscillators with a period of 24 h that is based on the output of transcriptional and post-translational feedback loops. Phosphorylation is considered one of the most important post-translational modifications affecting rhythmicity from cyanobacteria to mammals. For example, the lack of cyclin-dependent kinase 5 (CDK5) shortened the period length of the circadian oscillator in the Suprachiasmatic Nuclei (SCN) of mice via the destabilization of the PERIOD 2 (PER2) protein. Here, we show that CDK5 kinase activity and its interaction with clock components, including PER2 and CLOCK, varied over time in mouse embryonic fibroblast cells. Furthermore, the deletion of Cdk5 from cells resulted in a prolonged period and shifted the transcription of clock-controlled genes by about 2 to 4 h with a simple delay of chromatin binding of ARNTL (BMAL1) CLOCK. Taken together, our data indicate that CDK5 is critically involved in regulating the circadian clock in vitro at the molecular level.
      Citation: Clocks & Sleep
      PubDate: 2022-03-09
      DOI: 10.3390/clockssleep4010017
      Issue No: Vol. 4, No. 1 (2022)
  • Clocks & Sleep, Vol. 4, Pages 202-207: Sleep Deprivation Does Not
           Influence Photic Resetting of Circadian Activity Rhythms in Drosophila

    • Authors: David C. Negelspach, Sevag Kaladchibachi, Hannah K. Dollish, Fabian-Xosé Fernandez
      First page: 202
      Abstract: Previous investigations in humans and rodent animal models have assessed the interplay of sleep in the circadian system’s phase responses to nighttime light exposure. The resulting data have been mixed, but generally support a modulatory role for sleep in circadian photic resetting (not an absolute requirement). Drosophila have been historically used to provide important insights in the sleep and circadian sciences. However, no experiments to date have evaluated how immediate sleep need or recent sleep history affects their pacemaker’s phase readjustments to light. We did so in the current study by (1) forcing separate groups of animals to stay awake for 1 or 4 h after they were shown a broadspectrum pulse (15 min during the first half of the night, 950 lux), or (2) placing them on a restricted sleep schedule for a week before light presentation without any subsequent sleep disruption. Forced sleep restriction, whether acute or chronic, did not alter the size of light-induced phase shifts. These data are consistent with observations made in other diurnal animals and raise the possibility, more broadly, that phototherapies applied during sleep—such as may be necessary during the winter months—may still be efficacious in individuals experiencing sleep-continuity problems such as insomnia.
      Citation: Clocks & Sleep
      PubDate: 2022-03-21
      DOI: 10.3390/clockssleep4010018
      Issue No: Vol. 4, No. 1 (2022)
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