Publications by authors named "Leandro Casiraghi"

Article Synopsis
  • Sleep capital is vital for individual and societal well-being, affecting cognitive abilities, mental health, and productivity, which in turn influences economic outcomes.
  • The framework presented explores the link between sleep quality, health, and economic productivity, highlighting significant benefits from investing in sleep health initiatives.
  • Policy recommendations and strategies for workplaces and individuals are proposed to enhance sleep health, emphasizing its importance for a healthier and more productive society.
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  • There is an increasing interest in creating artificial light that activates specific retinal cells to help regulate circadian rhythms and improve overall well-being.
  • Researchers have focused on utilizing a photopigment called melanopsin but also discovered that color vision circuits in primates can transmit blue-yellow signals to these retinal cells.
  • A study found that using a specially designed light that alternates between short and long wavelengths resulted in a significant circadian phase shift in participants, outperforming traditional white light exposure in regulating sleep patterns.
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  • Nocturnal aversive stimuli can cause mice to shift their activity patterns towards the daytime, particularly when they're eating and drinking outside their safe nest.
  • The study reveals that an intact molecular circadian clock is essential for this fear-induced change in behavior, but it alone isn’t enough to maintain the altered rhythms.
  • The findings suggest that fear and anxiety disorders may disrupt circadian rhythms, indicating that a fear-entrained clock can lead to lasting disruptions in sleep and activity patterns even after the fear stimulus is removed.
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The suprachiasmatic nucleus (SCN) of the hypothalamus is the site of a central circadian clock that orchestrates overt rhythms of physiology and behavior. Circadian timekeeping requires intercellular communication among SCN neurons, and multiple signaling pathways contribute to SCN network coupling. Gamma-aminobutyric acid (GABA) is produced by virtually all SCN neurons, and previous work demonstrates that this transmitter regulates coupling in the adult SCN but is not essential for the nucleus to sustain overt circadian rhythms.

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  • The study explored how exposure to late evening electric light (LEEL) impacts sleep regularity in adolescents from rural communities in Argentina and Brazil.
  • Researchers measured sleep patterns using the Sleep Regularity Index and found that adolescents with LEEL exposure experienced delayed sleep onset, shorter sleep duration, and significantly lower sleep regularity scores.
  • The findings suggest that irregular sleep patterns should be added to the known negative effects of evening light on adolescents' sleep behaviors.
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  • * The study reveals that the molecular circadian clock is essential for this fear-entrained behavior, but having a functional clock in the SCN alone is not enough to maintain these changes.
  • * The findings suggest that the changes in circadian rhythms and sleep patterns typically seen in fear and anxiety disorders may be influenced by a circadian clock that has been altered through fear responses.
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  • Researchers are exploring artificial lighting that can enhance circadian rhythms by targeting intrinsically photosensitive retinal ganglion cells (ipRGCs) to improve mood, sleep, and overall health.
  • The study highlights a new lighting design that stimulates color-opponent inputs to ipRGCs by alternating between short and long wavelengths, particularly focusing on short-wavelength sensitive cones.
  • Results show that a two-hour exposure to this specially designed light led to an average circadian phase advance of 1 hour and 20 minutes in participants, demonstrating its potential effectiveness over traditional white light in regulating circadian rhythms.
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Article Synopsis
  • Human sleep is primarily influenced by light through the light-dark cycle, which regulates sleep timing, and by light's ability to inhibit sleep.
  • Modern living environments expose people to artificial light, disrupting natural sleep patterns and often leading to delayed sleep onset.
  • Studies of both indigenous communities with limited electricity and urbanized areas reveal widespread reductions in sleep duration due to increased access to artificial light, highlighting important findings and their limitations.
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  • Before artificial lights, moonlight was the main light source influencing night activities, but its effect on sleep timing is debated.
  • A study using wrist actimetry showed that people's sleep patterns align with the lunar cycle, regardless of their living environment, from rural communities in Argentina to urban settings in the U.S.
  • The findings indicate that nights leading up to the full moon have later sleep start times and shorter sleep durations, suggesting that moonlight may have historically increased nighttime activity and reduced sleep in preindustrial societies.
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  • The transition from nomadic lifestyles to industrialized societies was driven by the creation of artificially lit environments, allowing extended activity during the night and altering sleep patterns.
  • A study of two Toba/Qom communities in Argentina, one with electricity and one without, revealed that access to artificial light resulted in later sleep onset and shorter sleep durations.
  • The research shows a significant impact of artificial light on sleep physiology, specifically indicating a delayed melatonin onset in those with electricity, particularly in winter, highlighting changes in the human circadian system.
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Sleep health has multiple dimensions including duration, regularity, timing, and quality [1-4]. The Coronavirus 2019 (COVID-19) outbreak led to Stay-at-Home orders and Social Distancing Requirements in countries throughout the world to limit the spread of COVID-19. We investigated sleep behaviors prior to and during Stay-at-Home orders in 139 university students (aged 22.

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Circadian disruption has been linked to markers for poor health outcomes in humans and animal models. What is it about circadian disruption that is problematic? One hypothesis is that phase resetting of the circadian system, which occurs in response to changes in environmental timing cues, leads to internal desynchrony within the organism. Internal desynchrony is understood as acute changes in phase relationships between biological rhythms from different cell groups, tissues, or organs within the body.

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While social zeitgebers are known to shape diurnal preference, little research has been devoted to determining the contribution of the familiar group chronotype as social zeitgeber on individual circadian rhythms and sleep-wake patterns in adult subjects. The current study aimed to examine the matching between perceived family chronotype and individual chronotype and their relationship with sleep-wake patterns on weekdays and weekends, diurnal subjective somnolence, and substance consumption. Nine hundred and forty-two Colombian adults completed the Composite Scale of Morningness, the Epworth Sleepiness Scale, and responded to a questionnaire about circadian preferences of their family nucleus.

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Among the factors that contribute to the onset and maintenance of depressive disorders, rhythmicity of symptoms and consumption of caffeine have recently gained attention. The current study aimed to examine the differential rhythmicity of relevant variables in a sample of young participants, considering the presence of depressive symptomatology and the frequency of caffeinated drinks consumption. A significant 24-hour differential rhythmicity of mood, cognitive and physiological variables was found indicating an evening peak pattern in the participants with depressive symptoms.

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In all domains, from informal to formal, there are conflicts about property and ownership which resolution demands consideration of alleged claims from more than one party. In this work we asked adults ( = 359) to judge cases in which a character held a property claim over an item, but is challenged by a second character who holds a different, subsequent claim over it. The specific goal of this work is to investigate how the resolution of such conflicts depends on the social endorsement of ownership claims.

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Daily interactions between the hypothalamic circadian clock at the suprachiasmatic nucleus (SCN) and peripheral circadian oscillators regulate physiology and metabolism to set temporal variations in homeostatic regulation. Phase coherence of these circadian oscillators is achieved by the entrainment of the SCN to the environmental 24-h light:dark (LD) cycle, coupled through downstream neural, neuroendocrine, and autonomic outputs. The SCN coordinate activity and feeding rhythms, thus setting the timing of food intake, energy expenditure, thermogenesis, and active and basal metabolism.

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Metabolic functions are synchronized by the circadian clock setting daily patterns of food intake, nutrient delivery, and behavioral activity. Here, we study the impact of chronic jet-lag (CJL) on metabolism, and test manipulations aimed to overcome potential alterations. We recorded weight gain in C57Bl/6 mice under chronic 6 h advances or delays of the light-dark cycle every 2 days (ChrA and ChrD, respectively).

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Circadian rhythms are endogenous and need to be continuously entrained (synchronized) with the environment. Entrainment includes both coupling internal oscillators to external periodic changes as well as synchrony between the central clock and peripheral oscillators, which have been shown to exhibit different phases and resynchronization speed. Temporal desynchronization induces diverse physiological alterations that ultimately decrease quality of life and induces pathological situations.

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Diabetic retinopathy is a leading cause of blindness. Intrinsically photosensitive retinal ganglion cells (ipRGCs), which express the photopigment melanopsin, are involved in non-image-forming visual responses such as photoentrainment of circadian rhythms and pupillary light reflex. Since several reports indicate that retinal ganglion cells are affected by diabetes, we investigated the non-image-forming visual system in an advanced stage of experimental diabetes in rats induced by streptozotocin.

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We studied locomotor activity rhythms of C57/Bl6 mice under a chronic jet lag (CJL) protocol (ChrA(6/2) ), which consisted of 6-hour phase advances of the light-dark schedule (LD) every 2 days. Through periodogram analysis, we found 2 components of the activity rhythm: a short-period component (21.01 ± 0.

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Background: Recent evidence suggests a two-way interaction between the immune and circadian systems. Circadian control of immune factors, as well as the effect of immunological variables on circadian rhythms, might be key elements in both physiological and pathological responses to the environment. Among these relevant factors, galectin-1 is a member of a family of evolutionarily-conserved glycan-binding proteins with both extracellular and intracellular effects, playing important roles in immune cell processes and inflammatory responses.

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