Effects of lockdown on human sleep and chronotype during the COVID-19 pandemic

COVID-19 lockdown induced severe changes in light exposure and social cues. Leone et al. show that sleep is later and longer on weekdays with lower social jetlag during lockdown compared with a control condition in the same subjects (n = 1021). Sleep quality is not affected but chronotype is later, which might eventually lead to desynchronization.Fil: Leone, Maria Juliana. Universidad Torcuato Di Tella; Argentina. Universidad Nacional de Quilmes; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Sigman, Mariano. Universidad Torcuato Di Tella; Argentina. Universidad Nebrija; España. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Golombek, Diego Andrés. Universidad Nacional de Quilmes; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Paying the circadian toll: The circadian response to LPS injection is dependent on the Toll-like receptor 4

Systemic low doses of the endotoxin lipopolysaccharide (LPS) administered at CT15 (circadian time 12 corresponds to locomotor activity onset) induce phase delays of locomotor activity rhythms in mice. To evaluate if this effect was mediated by the Toll-like receptor 4 (TLR4), our present aim was to characterize the circadian behavior and LPS-induced circadian response of TLR4 (LPS receptor)-deficient mice (in C57bl/10 and C3H backgrounds). In mutants, we observed a free-running period and a light-induced phase delay similar to the one observed in their corresponding wild-type (WT) littermates. The LPS-induced phase delay, wheel running inhibition and c-Fos/Per-1 immunoreactivity in the paraventricular nuclei observed in WT mice was absent or significantly decreased in the TLR4-deficient mice. In conclusion, we show that LPS-induced circadian responses are mediated by TLR4.Fil: Paladino, Natalia. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología. Laboratorio de Cronobiología; ArgentinaFil: Leone, Maria Juliana. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología. Laboratorio de Cronobiología; ArgentinaFil: Plano, Santiago Andrés. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología. Laboratorio de Cronobiología; ArgentinaFil: Golombek, Diego Andres. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología. Laboratorio de Cronobiología; Argentin

Role of proinflammatory cytokines on lipopolysaccharide-induced phase shifts in locomotor activity circadian rhythm

We previously reported that early night peripheral bacterial lipopolysaccharide (LPS) injection produces phase delays in the circadian rhythm of locomotor activity in mice. We now assess the effects of proinflammatory cytokines on circadian physiology, including their role in LPS-induced phase shifts. First, we investigated whether differential systemic induction of classic proinflammatory cytokines could explain the time-specific behavioral effects of peripheral LPS. Induction levels for plasma interleukin (IL)-1α, IL-1β, IL-6, or tumor necrosis factor (TNF)-α did not differ between animals receiving a LPS challenge in the early day or early night. We next tested the in vivo effects of central proinflammatory cytokines on circadian physiology. We found that intracerebroventricular (i.c.v.) delivery of TNF-α or interleukin IL-1β induced phase delays on wheel-running activity rhythms. Furthermore, we analyzed if these cytokines mediate the LPS-induced phase shifts and found that i.c.v. administration of soluble TNF-α receptor (but not an IL-1β antagonistic) prior to LPS stimulation inhibited the phase delays. Our work suggests that the suprachiasmatic nucleus (SCN) responds to central proinflammatory cytokines in vivo, producing phase shifts in locomotor activity rhythms. Moreover, we show that the LPS-induced phase delays are mediated through the action of TNF-α at the central level, and that systemic induction of proinflammatory cytokines might be necessary, but not sufficient, for this behavioral outcome.Fil: Leone, Maria Juliana. Universidad Nacional de Quilmes; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Marpegan, Luciano. Universidad Nacional de Quilmes; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Duhart, José Manuel. Universidad Nacional de Quilmes; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Golombek, Diego Andres. Universidad Nacional de Quilmes; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Ten golden rules for optimal antibiotic use in hospital settings: the WARNING call to action

Antibiotics are recognized widely for their benefits when used appropriately. However, they are often used inappropriately despite the importance of responsible use within good clinical practice. Effective antibiotic treatment is an essential component of universal healthcare, and it is a global responsibility to ensure appropriate use. Currently, pharmaceutical companies have little incentive to develop new antibiotics due to scientific, regulatory, and financial barriers, further emphasizing the importance of appropriate antibiotic use. To address this issue, the Global Alliance for Infections in Surgery established an international multidisciplinary task force of 295 experts from 115 countries with different backgrounds. The task force developed a position statement called WARNING (Worldwide Antimicrobial Resistance National/International Network Group) aimed at raising awareness of antimicrobial resistance and improving antibiotic prescribing practices worldwide. The statement outlined is 10 axioms, or “golden rules,” for the appropriate use of antibiotics that all healthcare workers should consistently adhere in clinical practice

Solar clock and school start time effects on adolescents' chronotype and sleep: A review of a gap in the literature

Circadian rhythms are entrained by external factors such as sunlight and social cues, but also depend on internal factors such as age. Adolescents exhibit late chronotypes, but worldwide school starts early in the morning leading to unhealthy sleep habits. Several studies reported that adolescents benefit from later school start times. However, the effect of later school start time on different outcomes varies between studies, and most previous literature only takes into consideration the social clock (i.e. local time of school starting time) but not the solar clock (e.g. the distance between school start time and sunrise). Thus, there is an important gap in the literature: when assessing the effect of a school start time on chronotype and sleep of adolescents at different locations and/or seasons, the solar clock might differ and, consistently, the obtained results. For example, the earliest school start time for adolescents has been suggested to be 08:30 hours, but this school start time might correspond to different solar times at different times of the year, longitudes and latitudes. Here, we describe the available literature comparing different school start times, considering important factors such as geographic position, nationality, and the local school start time and its distance to sunrise. Then, we described and contrasted the relative role of both social and solar clocks on the chronotype and sleep of adolescents. As a whole, we point and discuss a gap in literature, suggesting that both clocks are relevant when addressing the effect of school start time on adolescents´ chronotype and sleep.Fil: Rodriguez Ferrante, Guadalupe. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Torcuato Di Tella; Argentina. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología. Laboratorio de Cronobiología; ArgentinaFil: Leone, Maria Juliana. Universidad Torcuato Di Tella. Escuela de Gobierno; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

The perfect hurricane in Latin America: school start time, chronotype, sleep, and academic performance during adolescence

Circadian rhythms are modulated by age. The timing of the circadian clock under real-life conditions (i.e., chronotype) is progressively delayed during adolescence. However, schools start very early in the morning, when the adolescent’ clock is still not prepared to be awake. Consistently, the misalignment between early school timing and late chronotypes leads to poor sleep: both short and out-of-time, which is associated with adverse consequences for health and cognitive and academic performance. This situation worsens in some countries due to cultural differences: Argentinian adolescents have even later chronotypes than most of their peers around the globe. Later school start times are associated with better sleep and a lower impact of chronotype on academic performance. Several strategies are suggested to evaluate and to mitigate the consequences of the misalignment between chronotype and school timing. Importantly, local studies and interventions are the key to understand and improve adolescents’ education and well-being.Fil: Rodriguez Ferrante, Guadalupe. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Goldin, Andrea Paula. Universidad Torcuato Di Tella; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Leone, Maria Juliana. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

The Tell-Tale Heart: heart rate fluctuations index objective and subjective events during a game of chess

During a decision making process, the body changes. These somatic changes have been related to specific cognitive events and also have been postulated to assist decision making indexing possible outcomes of different options. We used chess to analyze heart rate (HR) modulations on specific cognitive events. In a chess game, players have a limited time-budget to make about 40 moves (decisions) that can be objectively evaluated and retrospectively assigned to specific subjectively perceived events, such as setting a goal and the process to reach a known goal. We show that HR signals events: it predicts the conception of a plan, the concrete analysis of variations or the likelihood to blunder by fluctuations before to the move, and it reflects reactions, such as a blunder made by the opponent, by fluctuations subsequent to the move. Our data demonstrate that even if HR constitutes a relatively broad marker integrating a myriad of physiological variables, its dynamic is rich enough to reveal relevant episodes of inner thought

The geometry of expertise

Theories of expertise based on the acquisition of chunk and templates suggest a differential geometric organization of perception between experts and novices. It is implied that expert representation is less anchored by spatial (Euclidean) proximity and may instead be dictated by the intrinsic relation in the structure and grammar of the specific domain of expertise. Here we set out to examine this hypothesis. We used the domain of chess which has been widely used as a tool to study human expertise. We reasoned that the movement of an opponent piece to a specific square constitutes an external cue and the reaction of the player to this "perturbation" should reveal his internal representation of proximity. We hypothesized that novice players will tend to respond by moving a piece in closer squares than experts. Similarly, but now in terms of object representations, we hypothesized weak players will more likely focus on a specific piece and hence produce sequence of actions repeating movements of the same piece. We capitalized on a large corpus of data obtained from internet chess servers. Results showed that, relative to experts, weaker players tend to (1) produce consecutive moves in proximal board locations, (2) move more often the same piece and (3) reduce the number of remaining pieces more rapidly, most likely to decrease cognitive load and mental effort. These three principles might reflect the effect of expertise on human actions in complex setups. © 2014 Leone, Fernandez Slezak, Cecchi and Sigman.Fil: Leone, Maria Juliana. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Física. Laboratorio de Neurociencia Integrativa; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Física de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Física de Buenos Aires; ArgentinaFil: Fernandez Slezak, Diego. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Computación; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Física de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Física de Buenos Aires; ArgentinaFil: Cecchi, Guillermo Alberto. Thomas J. Watson Research Center; Estados UnidosFil: Sigman, Mariano. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Física de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Física de Buenos Aires; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Física. Laboratorio de Neurociencia Integrativa; Argentina. Universidad Torcuato Di Tella; Argentin