Chronobiology ePosters

The mammalian neuronal activity during sleep consists of two main states: non-rapid-eye-movement (NREM), also called slow-wave, and rapid-eye-movement (REM), also called active or paradoxical. The mechanisms underlying this ultradian sleep rhythm are not well understood but likely depend on reciprocal interactions…

In drosophila neurons, information flows from the soma to the active zones, electron-dense regions decorated with conserved molecules, including BRP. BRP sits vis-a-vis postsynaptic Glutamate receptors. Despite comprehensive studies highlighting their importance in synaptic transmission, there has yet to be a study…

The circadian rhythm and sleep architecture of senescence-accelerated mice (SAM)P8 and SAMR1 were evaluated to utilize SAM as a model of age-related sleep disorders. The evaluation of the circadian rhythm based on the locomotor activity was performed from 1 to 5 months old SAMP8 and SAMR1. At 6 months of age, mice…

Genomic imprinting controls fundamental brain functions in the 24-hour, including circadian rhythm, which is formed along with corticogenesis in early development. However, how imprinted genes regulate these crucial processes in mammals remains elusive. In this study, we investigated the contribution of the maternal…

Recent studies have revealed an essential contribution of cortical astrocyte calcium activity in regulation of sleep depth and state transitions (Bojarskaite et al., 2020, Nat Comms; Vaidyanathan et al., 2021, Nat Comms). However, astrocytic activity is highly heterogeneous across brain regions, and it is unclear if…

Almost all body functions undergo circadian variations synchronized by light/dark cycle-regulated melatonin secretion from the pineal gland. Circadian disruption reduces melatonin secretion and increases the risk of diabetes and its complications, including anxiety. We aimed to study the effects of reduced daily light…

The sleep cycle alternates between REM (rapid eye movement) and NREM (non-rapid movement) sleep, which is a highly characteristic feature of sleep. However, the mechanisms by which this cycle is generated are totally unknown. We found that a periodic transient increase of dopamine (DA) level in the basolateral…

The noradrenergic locus coeruleus (LC) is a fundamental component in the regulation of brain states supporting wakefulness. However, the possibility that it also plays a role for sleep has been around for many years. Gaining a more profound understanding of LC activity in the sleeping brain is crucial for better…

Long-term recordings in patients and animal models reveal circadian and multidien (multiple days) rhythmicity in epilepsy. The underlying mechanisms of these cycles are not known. We are interested in predicting the onset of epileptic seizures over the scale of days. To this end, we performed chronic telemetric and…

Diabetes mellitus is a widespread disorder and hypoglycaemia is one of the most serious complications. The outcome might be influenced by several factors, such as the sex, previous fasting or the time of day when the episode occurs (see e.g. Somogyi effect). Our aim was to reveal these influencing factors using an…

Sleep quantity and quality change dramatically across the lifespan of altricial mammals born with immature brains such as humans and rodents (Logan 2019, Cirelli 2020, Blumberg 2005, Blumberg 2014). Despite a crucial role for healthy development, we still know quite little about developmental sleep – especially when…

Background: Epilepsy and seizures occurrence are closely interwoven with brain inflammation. The inflammatory response is largely mediated by microglia, which are under strong circadian regulation. Circadian rhythms are 24-hour variations in physiological function orchestrated by a network of autoregulatory genes,…

Aging has potent effects on many basic parameters of circadian rhythm and also are associated with impairments in learning and memory. Melatonin, a hormone mainly secreted in the pineal gland, is believed to restore circadian rhythm of clock genes in the suprachiasmatic nucleus during aging. The present study…

Almost daily we face stressful situations and the body reacts with various coping mechanisms. Consequently, glucocorticoids are released, leading to immunosuppression and a changed metabolism. However, if the stress becomes chronic, the coping systems can be maladaptively altered. In addition, glucocorticoid levels…

Introduction: The aim of this study was to investigate the role of "morningness" and "eveningness" chronotype preferences in the associated risk of sleep disorders and stress in international students. Methodology: The study was conducted at the University of Jaen, Spain (September-November 2023), with the…

In mammals, circadian rhythms are controlled by the central clock, suprachiasmatic nuclei (SCN) in the hypothalamus. The external light signal could entrain SCN through intrinsically photosensitive retinal ganglion cells (ipRGCs), a type of neuron in the retinal of mammalian eyes, by releasing glutamate. The…

Torpor is a controlled and reversible state characterized by lowered metabolic rate and body temperature. In ground squirrels, torpor induces dendritic spine retraction and re-localization of synaptic proteins, which restore upon arousal (von der Ohe et al., 2007). The emergence from torpor is followed by increased…

As high as 50% of Alzheimer’s disease patients experience “sundowning”, defined as an increase in severity of neuropsychiatric symptoms, including agitation, confusion, and anxiety selectively in the evening. While such symptoms influence the decision to institutionalize patients, few preclinical models for sundowning…

Primary mitochondrial diseases are caused by mutations in genes required for mitochondrial function. The primary mitochondrial disease complex I deficiency results from loss-of-function mutations in subunits of mitochondrial respiratory complex 1 and is the most common cause of childhood mitochondrial disease. Complex…

The Glymphatic system model describes how cerebral spinal fluid (CSF) bulk movement in and around the brain is mediated by changes in cerebral hemodynamics, thereby removing waste products. Physiological factors such as the sleep-wake cycle could influence its function. This system could play a decisive role in the…

Parkinson's disease (PD) is a chronic neurodegenerative disease that is up to 90% idiopathic and occurs randomly in the population, possibly due to environmental factors. It is characterized by the progressive loss of dopaminergic neurons in the brain region called substantia nigra pars compacta (SNpc). This results…

Comprehensive, continuous quantitative monitoring of intricately orchestrated physiological processes and behavioral states in living organisms provides an important tool for elucidating the function of neural circuits under healthy and diseased conditions, for defining the effects of potential drugs and treatments,…

Circadian disruption, notably sleep disturbances, serves as an early indicator of Alzheimer’s disease (AD), preceding symptoms like memory loss. The suprachiasmatic nucleus (SCN) governs biological rhythms and receives direct retinal input via melanopsin-expressing retinal ganglion cells (mRGCs) to synchronize with…

How is the retinal visual processing affected by the behavior and internal states of an animal? The structure and function of the vertebrate retina have been extensively studied ex vivo across species. Recent studies, however, demonstrated that the retina operates differently in vivo, especially in an awake condition.…