Chronobiology International最新文献

This review synthesizes the neurobiological basis of sleep-like states and circadian rhythm mechanisms observed in teleost fish. Fish exhibit a complex biological organisation in terms of sleep and circadian rhythms, neuroendocrine regulation, behavioural adaptation, and interaction with environmental stimuli. Sleep is expressed in many fish species as sleep-like states characterised by behavioural indicators such as decreased motor activity, increased response threshold to external stimuli, and rapid reversibility. This process is regulated by both homeostatic sleep pressure and the circadian clock, which is sensitive to the light-dark cycle. Sleep deprivation in fish negatively affects cognitive performance by causing impairments in learning, memory consolidation, and synaptic plasticity processes. Furthermore, differences in sleep duration and responses to sleep homeostasis across species suggest that sleep physiology has been shaped by ecological and evolutionary adaptations. Thus, fish provide a powerful platform for elucidating the molecular architecture of circadian regulation and for exploring how environmental stressors influence neural function and behavior.

Circadian rhythm sleep-wake disorders (CRSWD) are characterized by misalignment between the sleep-wake rhythm and the environmental day-night cycle, leading to disturbances in daily life. Melatonin and light therapy targeting circadian rhythms are generally used, but with limited efficacy. Recent studies have revealed that one-third or more of CRSWD patients with abnormal sleep-wake rhythm have normal melatonin rhythm, indicating the possible involvement of internal desynchronization, where circadian rhythm and sleep-wake rhythm dissociate. Aripiprazole (APZ) is a dopamine D2/D3 receptor partial agonist and has recently been shown effective to CRSWD. In this study, we explored the potential of APZ in treating mouse model of CRSWD. We use male C57/Black6 mice and first demonstrated APZ administered to the mice with normal sleep-wake rhythm increased sleep during the rest period and also increased wakefulness during the next active period. We next found APZ administered to the chronic methamphetamine (MAP)-treated mice with CRSWD like sleep phenotype synchronized their sleep-wake rhythm to the light-dark cycle. This entrainment was also accompanied by changes in sleep architecture. These findings brought insights into the mechanism how APZ acts on patients with CRSWD, especially with internal desynchronization.

This exploratory study aimed to better ascertain specific features of sleep and eating behaviors associated with migraine. A cross-sectional case-control approach was used with an online convenience sample; 86 individuals with migraine and 74 non-migraine individuals (mean age = 44 y.o., 90% female) were recruited via social media and university students in Ireland/UK between July 2023 and July 2024. Migraine status was determined by self-report of prior diagnosis by a health-care practitioner; no ICHD-3 interviews were performed. Individuals with migraine showed significantly lower self-regulation (2.95 ± .04 vs 3.17 ± .09, d = .45), reduced food fussiness (3.04 ± .08 vs. 2.4 ± .10, d = .84), and increased hunger (3.30 ± .08 vs. 3.00 ± .08, d = -.41). Both workdays (7:36 h ± 0:09 h vs. 6:57 h ± 0:09 h, d = -.52) and weekly average sleep duration (7:19 h ± 0:09 h vs. 7:44 h ± 0:08 h, d = -0.34) was significantly longer in individuals with migraine. Non-adjusted logistic regression analysis revealed that longer workday sleep duration (OR = .1.69 (95% CI = 1.12, -2.55), p = 0.013) was associated with increased odds of a migraine diagnosis; while greater self-regulation of eating (OR = 0.28, 95% CI (0.092, 0.88), p = 0.028) and greater food fussiness were associated with reduced odds of a migraine diagnosis (OR = 0.29, 95% CI (0.154, 0.54), p < 0.001). Additional intragroup results for individuals with migraine are also presented.

Ghrelin is a peptide hormone that plays a central role in short-term appetite regulation and energy balance. Its secretion is not only influenced by nutritional status but also shaped by circadian rhythms and habitual eating patterns. Ghrelin levels typically rise during fasting and decrease after meals, but they also follow a daily rhythm, peaking during the night and reaching their lowest levels in the morning. Human studies suggest that consistent meal schedules may entrain ghrelin secretion, with anticipatory rises occurring before habitual mealtimes. Experimental interventions show that morning-loaded eating patterns, compared to evening-loaded ones, lead to stronger postprandial ghrelin suppression, enhanced satiety hormone responses, and greater weight loss, even with similar caloric intake. In contrast, delayed or misaligned eating, such as during night-shift work, is associated with elevated ghrelin levels at biologically inappropriate times and increased hunger. Some studies have also highlighted the leptin-to-ghrelin ratio as a useful marker of appetite regulation and metabolic risk, particularly in overweight individuals. Together, these findings support the idea that the timing of food intake modulates ghrelin dynamics and influences metabolic outcomes. Meal timing, when aligned with endogenous biological rhythms, may therefore serve as a practical target for chrononutritional strategies aimed at improving appetite control and weight regulation.

There is a growing recognition of the impact of circadian rhythms on athletic performance, when teams crossing multiple time zones play at a different circadian alignment than their opponents. This study aimed to examine the association between circadian differences between NHL teams and increased penalty behavior. Data from NHL games played between 2009 and 2021 (n = 27,642) were analysed. A travel-adjusted time zone was computed for both teams, from which a Difference in alignment between teams was calculated: Ahead, same as, and behind opponent. A one-way ANOVA was done with the Difference in alignment on the number and minutes of penalties and results were significant for both variables. Post-hoc analyses revealed that teams behind received significantly fewer penalties (p < 0.001) than teams ahead or in the same time zone as their opponents (p < 0.001) and had fewer penalty minutes than teams who were in the same time zone as their opponent (p = 0.002). These results suggest that teams playing at a later point in their circadian cycle than their opponents were given more penalties, which highlights the importance of professional organisations understanding the potential influence of circadian rhythms and travel on behavior and performance outcomes during games.

Chronotype refers to an individual's natural preference for being active in the morning or evening and may influence physical and cognitive performance. This study examines its impact on balance, lower limb power, hand-eye coordination, and self-efficacy in collegiate athletes across morning and evening sessions. A total of 54 athletes (27 morning-type, 27 evening-type) completed physical, cognitive, and self-efficacy tests in two-time windows: early morning (07:00h-10:00h) and late afternoon (15:00h-18:00h) to assess time-of-day effects on performance. Morning chronotype exhibited superior performance in balance and lower limb power during morning sessions, while evening chronotypes excelled in these measures during evening sessions. Hand eye coordination and self-efficacy did not show significant changes across chronotypes or times of day, suggesting these abilities are less affected by the body's internal clock. These findings highlight the potential benefits of tailoring training schedules to an athlete's chronotype to enhance performance.

Circadian rhythms in the vertical distribution of adult zebrafish and their potential sensitivity to geomagnetic fluctuations remain poorly characterized. In this study, we investigated Danio rerio maintained under different light-dark regimes and exposed to natural diurnal geomagnetic variation (~30 nT, with a 24-h period) or slow magnetic oscillations (~100-150 nT, with periods of 26.8, 33.76, or 36 h). Behavioral endpoints included the proportion of time spent in the upper versus lower part of the water column and the frequency of midline crossings. Under standard and modified light-dark cycles, zebrafish exhibited a robust rhythm, occupying upper layers during darkness and shifting downward during the light phase. This pattern differs from that described for zebrafish in natural environments and probably reflects long-term adaptation to aquaculture. Under constant illumination, free-running rhythms with periods close to 24 h persisted across groups. Analysis of midline crossing frequency revealed a significant ~33.8 h rhythm in fish pre-exposed to the atypical 24:12 h light-dark cycle, consistent with the periodicity of the applied magnetic oscillation. These results suggest that geomagnetic fluctuations may function as an extremely weak zeitgeber compared to the dominant influence of the photoperiod. Prior exposure to an atypical light-dark regime, which may have reset the biochemical processes sustaining the endogenous oscillators, appears to be required for the manifestation of magnetically driven rhythm entrainment.

This study investigated the relationships between chronotype, physical activity, and fluid and nutrient intake in healthy young adults. A total of 935 participants (66.6% female), aged 18-30, were classified into morning, intermediate, or evening chronotypes using the Morningness - Eveningness Questionnaire. Physical activity was categorized as active or sedentary based on self-reported exercise frequency and duration. Nutrient intake was measured using 24-h dietary recall, a Food Frequency Questionnaire, and a structured fluid intake survey. Data collection occurred in June and July to minimize seasonal effects. Physically active individuals consumed significantly more water daily than sedentary participants (p < 0.001, η² = .088). They also reported higher intake of black tea, herbal tea, iced tea, Turkish coffee, and milk (all p < 0.001). Evening chronotype individuals consumed significantly less black tea and milk (both p < 0.001) but showed no significant difference in water intake (p = 0.088). Evening types were also linked to lower consumption of red meat (B = -0.38, p = 0.034) and fish (B = -0.58, p = 0.002), while the decrease in egg consumption was not statistically significant (p = 0.082). These results suggest that morning chronotype and physical activity correlate with healthier fluid intake patterns, whereas evening chronotype may reduce intake of some animal proteins. Overall, hydration and diet appear influenced by lifestyle and biological rhythms. The study highlights the need for personalized nutrition counseling that considers chronotype and physical activity to promote healthier behaviors.

Being alert and attentive is essential for cognitive control processing, as it facilitates the detection of conflicting stimuli that require resolution. Exposure to daytime artificial light increases alertness; however, the effects on conflict resolution, referred to as cognitive control, remain poorly understood, especially since previous studies have focused solely on averaged inter-individual measures such as mean reaction time. Intra-individual (within-person) reaction time variability (RTV) provides a moment-to-moment averaged measure that conveys information about the consistency of attentional focus throughout the process of detecting and resolving stimuli conflicts. This crossover study of healthy participants (N = 39, M_age = 21.7, SD_age = 2.6, 62% female) explored the acute effects of a 2 h morning exposure to "blue" short-wavelength light (1442 lx_m-EDI), "red" long-wavelength light (3.8 lx_m-EDI), and short-wavelength-enriched bright white light (1156 lx_m-EDI, ~ 8000 K), against a control condition of white dim light (<10 lx_m-EDI), on cognitive control measured with a flanker task. Compared to white dim light, "blue" light contributed to lower RTV during the processing of cognitive conflicts, but the effect was small and non-robust. Exposure to artificial light did not affect averaged inter-individual measures. Our preliminary findings suggest that "blue" light has the potential to stabilize attentional fluctuations during cognitive conflict processing; however, this potential should be further investigated in studies with larger samples.