Journal of Biological Rhythms最新文献

{"title":"Evolutionary Consequences of Selection on Circadian Accuracy.","authors":"Chitrang Dani","doi":"10.1177/07487304261438179","DOIUrl":"10.1177/07487304261438179","url":null,"abstract":"","PeriodicalId":15056,"journal":{"name":"Journal of Biological Rhythms","volume":" ","pages":"510-511"},"PeriodicalIF":3.0,"publicationDate":"2026-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13342459/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147645086","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Overnight Motor Memory Consolidation in Adolescents: Effects of Change in Dim Light Melatonin Onset After Sleep Restriction.","authors":"Lindsay Stager, Caroline Gredvig-Ardito, Stephanie Crowley, Ronald Seifer, Mary Carskadon, Jared Saletin","doi":"10.1177/07487304261427822","DOIUrl":"10.1177/07487304261427822","url":null,"abstract":"<p><p>Adolescents experience chronic sleep restriction and developmental changes in circadian biology. Sleep aids adolescent learning and memory; the moderating effect of circadian rhythms is largely unknown. Here we examine adolescent sleep restriction, circadian biology, and memory consolidation. Adolescents were recruited for a larger experimental study. This study includes a subsample of individuals from the larger study who completed the motor sequence task (MST; added toward the end of data collection). Participants (<i>M</i>_AGE = 12.7, <i>SD</i> = 1.8; 62.5% male) completed a self-selected 9 h in bed sleep stabilization schedule for 19 nights followed by 7 nights of sleep restriction (6 h in bed; bedtime delayed and risetime advanced equally). In-lab dim light melatonin onset (DLMO) was assessed on the final nights of stabilization and restriction. The MST indexed overnight memory consolidation across the final night of sleep restriction. MST outcomes included the average number of correct sequences per trial, # of errors, and precision. We examined overnight improvement (morning-evening) in MST performance and associations between improvement, phase preference, DLMO_{Stabilization}, DLMO_Restriction, and DLMO_Shift (DLMO_{Stabilization} - DLMO_Restriction), controlling for age where statistically justified. The average number of correct sequences per MST trial improved, <i>t</i>(15) = -3.44, <i>p</i> < 0.01, <i>d</i> = 0.86, for the morning (12.94 ± 6.89) test session compared to evening (10.81 ± 5.69). There were no changes in errors or precision (<i>d</i>s < 0.14, <i>p</i>s > 0.34). Greater delays in DLMO phase (<i>M</i> ± <i>SD</i>: 10.34 ± 41.69 min) were associated with greater overnight improvement in the average number of correct sequences per trial, Adj. <i>R</i>² = 0.54, <i>F</i>(2, 13) = 9.79, <i>p</i> < 0.01, and errors, Adj. <i>R</i>² = 0.21, <i>F</i>(1, 15) = 4.94, <i>p</i> < 0.05. Overnight improvement was not related to phase preference (Adj. <i>R</i>²s < 0.17; <i>p</i>s > 0.05). These data highlight context dependent benefits of sleep for adolescent memory consolidation and indicate a potential link between circadian biology and the cognitive benefits of adolescent sleep. Understanding the influence of circadian rhythms in sleep-dependent memory may inform discussions of adolescent sleep loss and learning.</p>","PeriodicalId":15056,"journal":{"name":"Journal of Biological Rhythms","volume":" ","pages":"502-509"},"PeriodicalIF":3.0,"publicationDate":"2026-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13060023/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147627052","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Lentiviral Fluorescent Reporter to Study Circadian Rhythms in Single Cells.","authors":"Christian H Gabriel, Luis Lehmann, Joana Ahlburg, Achim Kramer","doi":"10.1177/07487304261431992","DOIUrl":"10.1177/07487304261431992","url":null,"abstract":"<p><p>Circadian rhythms-self-sustained, ~24-h oscillations in transcript and protein levels-are generated by a cell-autonomous molecular clock. These rhythms shape how individual cells respond to external signals, influencing key decisions such as differentiation and apoptosis. However, current tools for visualizing circadian rhythms at the single-cell level often rely on genomic engineering and clonal expansion, limiting their accessibility and applicability. We present fluorescent circadian reporters based on the murine <i>REVERBα/Nr1d1</i> gene, delivered via lentiviral transduction and compatible with time-lapse single-cell microscopy. These reporters produce oscillatory signals that depend on a functional circadian clock and can be used to determine a cell's circadian dynamics parameters, such as circadian phase. Their simple and efficient delivery should make them suitable for a wide variety of cell types, greatly expanding opportunities to study single-cell circadian dynamics and their impact across diverse biological processes and systems.</p>","PeriodicalId":15056,"journal":{"name":"Journal of Biological Rhythms","volume":" ","pages":"477-486"},"PeriodicalIF":3.0,"publicationDate":"2026-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13342504/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147772220","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Variable Morning Melatonin Profiles Limit Determination of Dim-Light Melatonin Offset in Preschool-Aged Children.","authors":"Lauren E Hartstein, Shelby R Stowe, Kenneth P Wright, Cecilia Diniz Behn, Monique K LeBourgeois","doi":"10.1177/07487304261469609","DOIUrl":"10.1177/07487304261469609","url":null,"abstract":"<p><p>Circadian rhythms have been shown to regulate sleep-wake timing across the lifespan, yet many questions remain about early childhood circadian physiology. Understanding dim-light melatonin onset (DLMO) and offset (DLMOff), established markers of circadian phase, is essential for characterizing circadian rhythms in early childhood. We examined the distribution of salivary DLMO and DLMOff and their relationship with actigraphic sleep timing across 20 healthy preschoolers (M = 4.31 ± 0.34 years, 45% female). After maintaining a consistent sleep schedule for 7 days, children completed an in-home circadian assessment. Children were awoken 1.5 h before habitual wake time, and saliva samples were collected in 20- to 30-min intervals throughout the morning to determine DLMOff, then in the evening until 50 min past habitual bedtime to assess DLMO. A 4-pg/ml threshold was used to calculate each phase marker. DLMO ranged from 17:22 to 20:40 (M = 18:55 ± 0:54) and was positively associated with bedtime, sleep onset, and midsleep. In contrast, morning melatonin levels were highly variable, allowing DLMOff calculation in only 8 participants. Within this small subsample, later DLMOff was associated with later chronotype (<i>r</i> = 0.81), sleep offset (<i>r</i> = 0.84), and midsleep (<i>r</i> = 0.80). Across the full sample, interpolated melatonin levels at habitual wake remained ≥ 4 pg/ml for 45% of children, a pattern broadly consistent with findings in adults, in which a majority of participants exhibit DLMOff after habitual wake time. These findings indicate that although evening melatonin profiles were consistently well-defined, permitting reliable calculations of DLMO across all participants, morning melatonin patterns were often irregular in young children. When able to be calculated, DLMOff showed strong associations with sleep timing, suggesting it could be a reliable marker of circadian phase. However, high variability and fluctuating morning melatonin patterns make DLMOff difficult to determine in many preschool-aged children.</p>","PeriodicalId":15056,"journal":{"name":"Journal of Biological Rhythms","volume":" ","pages":"7487304261469609"},"PeriodicalIF":3.0,"publicationDate":"2026-07-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13410957/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148591738","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Seasonality of Mass Shooting Events and Deaths by Suicide in the United States, 2014 to 2021.","authors":"Mark É Czeisler, Charles A Czeisler","doi":"10.1177/07487304261464399","DOIUrl":"https://doi.org/10.1177/07487304261464399","url":null,"abstract":"<p><p>It has been hypothesized that most mass shootings are suicidal acts, necessitating investigation of potentially common elements. We investigated whether US mass shootings and deaths by suicide during 1 January 2014 through 31 October 2021 exhibited significant seasonal variations. Outcomes included temporal patterns of mass shooting events and deaths by suicide and their relationship, as characterized by multivariable linear regression models detrended to isolate seasonality and estimate peak phases and amplitudes. Overall, 3,305 mass shootings and 360,827 deaths by suicide were analyzed. Detrended models revealed significant seasonal variation in mass shootings and deaths by suicide. Mass shootings and deaths by suicide displayed concurrent estimated annual peaks occurring on 3 July and 23 June, respectively. Detrended models estimated that at peak-versus-nadir, seasonality accounted for 613% increased mass shootings and 12% increased deaths by suicide. US mass shooting events and deaths by suicide exhibited strikingly synchronous seasonality, with concurrent mid-summer peaks and mid-winter nadirs. This finding calls for expanded implementation of summertime gun violence and suicide-prevention programs and for equipping treatment centers to respond to increased summertime demands. Further research is needed to investigate potential mechanisms underlying the shared seasonality and the hypothesis that many mass shootings are both homicidal and suicidal, intended as final acts.</p>","PeriodicalId":15056,"journal":{"name":"Journal of Biological Rhythms","volume":" ","pages":"7487304261464399"},"PeriodicalIF":3.0,"publicationDate":"2026-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148578696","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Latitudinal Clines in Diapause Onset and Circadian Clock Characteristics in <i>Drosophila littoralis</i> and <i>Drosophila montana</i>.","authors":"Giulia Manoli, Pekka Lankinen, Anneli Hoikkala, Charlotte Helfrich-Förster","doi":"10.1177/07487304261461316","DOIUrl":"https://doi.org/10.1177/07487304261461316","url":null,"abstract":"<p><p><i>Drosophila littoralis</i> and <i>Drosophila montana</i> are two widespread species of the <i>virilis</i> group that occur at latitudes between approximately 40°N and 70°N. To survive the winter, they undergo a photoperiodically controlled diapause triggered by the decreasing photoperiod in late summer to autumn. Previous studies have shown that the critical photoperiod at which diapause is triggered depends on latitude. Fly populations living at high latitudes have a longer critical photoperiod than populations living at low latitudes, meaning that they enter diapause earlier. It is not yet fully understood how fly species measure photoperiod, but there is increasing evidence that the circadian clock is involved in this process. A recent study on <i>D. littoralis</i> has shown that the properties of the circadian clock change with latitude in parallel with the latitudinal changes in critical photoperiod, supporting this hypothesis. In <i>D. montana</i>, latitudinal clines have been observed in several diapause-related traits that have not yet been studied in <i>D. littoralis</i>. However, it is not known whether <i>D. montana</i> populations exhibit similar latitudinal clines in circadian clock traits as <i>D. littoralis</i>. Here, we compare the circadian clock and diapause traits of <i>D. littoralis</i> strains from different latitudes in Europe and <i>D. montana</i> populations from different latitudes in North America, using previously published data and determining missing parameters. We show that the two species exhibit similar latitudinal clines in circadian clock traits such as rhythm strength and timing of evening activity, as well as in diapause-related traits such as critical photoperiod, critical temperature, post-reproductive diapause and stability of photoperiodic time-measurement, with minor differences in the correlation between latitude and the expression pattern of the neuropeptide pigment-dispersing factor. Overall, our findings give new insight into the role of the circadian clock in measuring photoperiods that are essential for diapause induction in both <i>Drosophila</i> species.</p>","PeriodicalId":15056,"journal":{"name":"Journal of Biological Rhythms","volume":" ","pages":"7487304261461316"},"PeriodicalIF":3.0,"publicationDate":"2026-07-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148535940","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Internal Circadian Misalignment of the Human Metabolome Links Night Shiftwork to Metabolic Impairment.","authors":"Michelle Kubicki, Andrew W McHill, Edward L Melanson, Nichole Reisdorph, Kenneth P Wright, Christopher M Depner","doi":"10.1177/07487304261459478","DOIUrl":"10.1177/07487304261459478","url":null,"abstract":"<p><p>Circadian misalignment, as experienced during shiftwork, impairs glucose metabolism and body weight regulation, yet the underlying biochemical mechanisms remain incompletely understood. Characterizing how circadian misalignment alters circulating metabolites provides a promising avenue to help identify these mechanisms. Although data from metabolomics studies have identified circulating metabolites with daily rhythms, it is not comprehensively known which rhythms shift during circadian misalignment and whether such shifts relate to metabolic impairment. We conducted 24-hour (h) metabolomic profiling every 4 h in 14 healthy adults (8 women) aged 26.4 ± 1.2 years (mean ± SD), undergoing a 6-day simulated night-shiftwork protocol. 24-h modeling analyses identified metabolite rhythms influenced by circadian versus behavioral cycles (sleep, food intake) and quantified internal circadian misalignment using acrophase shifts. Metabolic outcomes included glucose homeostasis (test meals) and energy expenditure (EE; whole-room calorimetry). Night-shiftwork produced widespread alterations in metabolite rhythms, with significant internal misalignment in multiple metabolites across pathways including pyrimidine metabolism, bile acid-microbiome signaling, and lipid metabolism. During misalignment, glucose and insulin area under the curve increased (<i>p</i> < 0.05) and EE decreased (<i>p</i> < 0.05). Internal misalignment of uridine and glycoursodeoxycholic acid was associated (<i>p</i> < 0.05) with impaired glucose tolerance, while their circulating concentrations were associated with decreased EE. Misalignment of uridine and glycoursodeoxycholic acid suggests dysregulated pyrimidine and bile acid-microbiome pathways as potential mechanisms linking circadian misalignment to cardiometabolic disease risk.</p>","PeriodicalId":15056,"journal":{"name":"Journal of Biological Rhythms","volume":" ","pages":"7487304261459478"},"PeriodicalIF":3.0,"publicationDate":"2026-07-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13501974/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148430500","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Buttheaded Editor: On Your Cover Letter to the Journal.","authors":"Erik D Herzog","doi":"10.1177/07487304261465776","DOIUrl":"https://doi.org/10.1177/07487304261465776","url":null,"abstract":"","PeriodicalId":15056,"journal":{"name":"Journal of Biological Rhythms","volume":" ","pages":"7487304261465776"},"PeriodicalIF":3.0,"publicationDate":"2026-07-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148430457","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Circadian Rhythm in Restless Legs Syndrome and Its Association With Symptom Severity: An Actigraphy-Based Study.","authors":"Se Young Bang, Aqsa Awan, Dongju Lim, Sungeun Hwang, Brian B Koo, Jae Kyoung Kim, Ki-Young Jung","doi":"10.1177/07487304261456963","DOIUrl":"10.1177/07487304261456963","url":null,"abstract":"<p><p>Restless legs syndrome (RLS) is characterized by an urge to move that occurs in the evening or night time, suggesting circadian involvement. However, objective evidence regarding the circadian phase in RLS remains limited, particularly in real-world settings. We conducted an exploratory pilot study to investigate circadian rhythm timing in patients with RLS using actigraphy-based dim light melatonin onset (DLMO) estimation and to explore its potential association with symptom severity. Patients with idiopathic RLS (<i>n</i> = 21) and age- and sex-matched chronic insomnia controls (<i>n</i> = 21) underwent 14 days of wrist actigraphy to assess rest-activity rhythms and obtain estimated DLMO (eDLMO) from an actigraphy-based mathematical model. Symptom severity was evaluated with the International RLS Study Group rating scale (IRLS). Group comparisons and correlation analyses were conducted in an exploratory manner given the sample size. Patients with RLS (mean age 61.2 ± 7.7 years, 90% female) demonstrated a non-significant trend toward delayed eDLMO compared with insomnia controls (mean age 61.7 ± 7.1 years, 90% female; 10:01 PM ± 47 min vs 9:33 PM ± 49 min, <i>p</i> = 0.069, Cohen's d = 0.58). Within the RLS group, higher IRLS scores were modestly associated with later eDLMO (β = 0.0726, <i>p</i> = 0.038), after adjusting for age and depressive symptoms. In contrast, eDLMO was not significantly associated with Insomnia Severity Index (ISI) or Pittsburgh Sleep Quality Index (PSQI) scores in the insomnia control group. In this exploratory pilot study, patients with RLS showed a tendency toward delayed estimated circadian phase compared with insomnia controls, and later estimated circadian phase was modestly associated with greater RLS symptom severity. These findings support a possible link between circadian phase delay and clinical burden in RLS but require confirmation in larger studies.</p>","PeriodicalId":15056,"journal":{"name":"Journal of Biological Rhythms","volume":" ","pages":"7487304261456963"},"PeriodicalIF":3.0,"publicationDate":"2026-07-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148404773","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Circadian Behavioral and Bioluminescence Rhythms in the <i>Per2^LUC</i> Syrian Hamster.","authors":"Yanan Liu, Elizabeth Roszkowski, Rong Li, Chip Sisson, Ella Landman, David R Weaver, Zhongde Wang, Jennifer A Evans, Eric L Bittman","doi":"10.1177/07487304261459487","DOIUrl":"10.1177/07487304261459487","url":null,"abstract":"<p><p>The use of genetically introduced optical reporters has improved understanding of circadian rhythms at the cellular and systems levels, but the use of this approach in mammals has been limited to mice and rats. The Syrian hamster (<i>Mesocricetus auratus</i>) has been a long-standing circadian model due to its rhythmic precision and physiological responses to photoperiod. Here we report the development of the <i>Per2^LUC</i> hamster, which harbors a knock-in construct inserted using the Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) technology. We test circadian and photoperiodic function at the behavioral level in the <i>Per2^LUC</i> hamster and evaluate ex vivo <i>Per2</i>-driven bioluminescence rhythms across a variety of tissues. Our results indicate modest effects of transgene insertion on circadian function in vivo and provide evidence that ex vivo <i>Per2</i>-driven bioluminescence rhythms are robust to dissection for many of the 10 tissues examined here. Properties of bioluminescence rhythms varied by tissue type in the <i>Per2^LUC</i> hamster, which was overall similar to those displayed by tissues collected from the <i>Per2^LUC</i> mouse. Collectively, these results indicate that this new animal model may be beneficial in both circadian and non-circadian applications in future studies.</p>","PeriodicalId":15056,"journal":{"name":"Journal of Biological Rhythms","volume":" ","pages":"7487304261459487"},"PeriodicalIF":3.0,"publicationDate":"2026-07-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13348727/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148404734","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}