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Hormonal synchronization of fetal circadian clocks in suprachiasmatic nuclei
Kapsdorferová, Viktória ; Sumová, Alena (advisor) ; Sehadová, Hana (referee)
Rhythmic non-light maternal signals, such as various behavioral, neurohumoral or metabolic factors, may play a key role in synchronization of the fetal circadian clock. This diploma thesis focuses more closely on the possible role of leptin and dopamine in the hormonal synchronization of the fetal central clock resides in the suprachiasmatic nuclei of the hypothalamus. A transgenic mouse fetus, which has luciferase fused to the clock gene Period 2, was used as an experimental model. This allowed us to monitor the operation of the fetal central clock in real time by recording the bioluminescence of tissue explants. Exogenous administration of dopamine during the decline in bioluminescence at normalized circadian time 15 induces larger phase delays compared to vehicle. Leptin, on the other hand, can participate in the development of spontaneous rhythms by stabilizing the integrity of the circadian rhythm, manifested by slowing down the rhythm dampening. At the level of individual cellular oscillators, significant regional differences in amplitude and period were not observed using bioluminescence microscopy. However, a slight dispersion of cell phases was observed after administration of dopamine during decreasing bioluminescence. In the case of leptin, there was a prolongation of period of the cell...
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Development of the circadian system after systemic potentiation of GABAergic transmission in early ontogenesis
Dušek, Jakub ; Bendová, Zdeňka (advisor) ; Mareš, Pavel (referee)
The circadian system is the evolutionary response of organisms to repetitive geophysical conditions and allows organisms to devote their energy to solving sudden changes. Although the circadian system developed to help organisms survive and thrive in dynamic conditions, system itself is sensitive to external changes. During critical developmental period of the mammalian CNS, the neonatal period, the circadian systém is significantly vulnerable. Benzodiazepines, pharmaceuticals widely prescribed for half a century, interfere with GABAergic transmission, which is critical type of signaling for the functioning of the circadian systém. The purpose of this thesis is to determine whether and how the development and functioning of the circadian system is altered after administration of a drug from the benzodiazepine class, clonazepam, during the critical developmental period. This thesis examines changes in the expression profile of selected genes in the hippocampus, olfactory bulb and frontal cortex of two ontogenetic stages of rats. Results of this work suggest that benzodiazepines administred in the neonatal period disrupt the development of the circadian system and that these changes, particularly in the hippocampus, persist for certain time. Key words: circadian system; circadian rhythms;...
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Circadian rhythms in adipocytes and impact of their disruption
Zavřelová, Michaela ; Sumová, Alena (advisor) ; Spišská, Veronika (referee)
This bachelor thesis deals with circadian rhythms in adipocytes and the consequences of their disruption. The thesis summarizes current scientific knowledge and explores the mechanism of rhythm control at the molecular level, which is formed by transcriptional translational feedback loops. Adipocytes control lipid metabolism through the production of adipokines, adipogenesis, lipogenesis, and lipolysis. The research focuses on how clock genes are involved in these processes. All of these events, which are characteristic of adipocytes, are highly regulated and the genes that are involved in them are transcriptionally activated by clock gene proteins. Circadian rhythms are an integral part of our lives, and desynchronization of rhythms between the main oscillator, which is the suprachiasmatic nuclei, and peripheral adipocytes can lead to metabolic disorders, which in turn can lead to obesity, insulin resistance, or type 2 diabetes. Obesity is one of the biggest problems of modern society, and disrupted circadian rhythms due to today's lifestyle are one of the causes of its development. Key words: circadian rhythms, clock genes, adipocytes, obesity, PPARγ, adipogenesis, lipogenesis, lipolysis, leptin, adiponectin
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Influence of binaural beats on ideomotoric coordination
Pavlovič, Ondřej ; Pánek, David (advisor) ; Pavlů, Dagmar (referee)
Name: The effects of binaural beats on sleep quality: a systematic review Aims of the study: The main objective of this study is to present the possibilities of influencing stress and sleep, to determine the effect of binaural beats (BB) stimulation on sleep quality and parameters, and to determine the specifics of effective BB therapy based on the available data. Materials and methods: This systematic review includes scientific articles and clinical studies published in relevant and/or peer-reviewed journals and conference proceedings. Three electronic databases (Web of Science, Scopus, PubMed) were searched for all available sources published from 2000 to January 2023 in English language. The search was conducted using relevant keywords and their combinations. The screening and subsequent process of elimination was based on set of eligibility and inclusion criteria. Results: Total of fourteen studies met the eligibility criteria. BB stimulation increased subjectively perceived sleep quality and reduced mental tension. Objectively, it reduces time of falling asleep, accelerates the onset of deeper sleep stages (N2 and N3) and increases their duration, as well as the total sleep time. The parameters optimal for effective BB stimulation can be laid out as follows: BB in the frequency range of 2 to 4...
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The measurement of melanopic quantities in indoor spaces with the luminance analyser LDA - LumiDISP
Siegel, Josef ; Baxant, Petr (referee) ; Motyčka, Martin (advisor)
This thesis focuses on measuring melanopic quantities in indoor spaces and their impact on individuals and their circadian rhythms. Melanopic quantities are specific parameters of light that influence biological responses and physiological processes in our bodies. To measure these quantities, a photometric analyzer is utilized, enabling the quantification of spectral components of light. It also evaluates the melanopic contributions of various lighting sources, such as LED fixtures, incandescent bulbs, or natural daylight.
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The sleep hygiene in men serving imprisonment
HULÁK, Pavel
The diploma thesis is focused on sleep hygiene of men serving a prison sentence. Its main goal is to set recommendations for professional staff in terms of sleep hygiene of convicted men in a specific prison environment. A partial goal is to determine the quality of sleep in selected men serving a prison sentence and by what factors their sleep is most affected and whether these men know the concept of sleep hygiene and follow its rules. The theoretical part defines the concept of resocialization and also provides more information about the execution of a sentence. The main part of the work deals with the physiology of sleep and sleep hygiene, while there is also a list off actors affecting the quality of sleep. This part of the work concludes with a description of the most common harmful habits affecting sleep in prison. The empirical part of the work, using a quantitative approach in research, made it possible to meet all the stated goals, but the hypotheses set for this research were all refuted. However, one third of respondents (35 %) report sleep problems, 27 % attribute a negative share to falling asleep to prison stress and 34 % admit fatigue as a physical consequence of not sleeping.
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Circadian changes of the cholinergic system in various areas of the central nervous system
Křížová, Monika ; Mysliveček, Jaromír (advisor) ; Jakubík, Jan (referee)
Muscarinic acetylcholine receptors type 4 are one of the five subtypes of metabotropic muscarinic receptors whose knockout led to disruption of the biorhythm represented by locomotion in female mice. In this thesis, we attempted to determine the biorhythmic activity of selected components of the cholinergic system in structures of the central nervous system which are suspected to regulate circadian locomotion. These selected structures were the striatum, motor cortex, thalamus, intergeniculate leaflet, subparaventricular zone and posterior hypothalamic area. Changes of muscarinic receptor density in wild type and M4 receptor knockout female mice were measured by using autoradiography throughout the day. In the striatum, motor cortex, and thalamus, the density of muscarinic receptors type 1 and the activity of acetyl- and butyrylcholinesterases were also measured by autoradiography and the Ellman's method. Rhythmic oscillations of muscarinic receptor density were observed in all structures selected in both types of mice. The main brain structure responsible for the differences in the biological rhythm of wild type and M4 receptor knockout mice was identified as the striatum and motor cortex region, where the percentage of M4 receptors was highest. Diurnal oscillations were also exhibited by...
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Expression of AMPA glutamate receptor subunits in the suprachiasmatic nucleus of the rat
Červená, Kateřina ; Bendová, Zdeňka (advisor) ; Zemková, Hana (referee)
The main mammalian circadian pacemaker stored in suprachiasmatic nuclei of the hypothalamus (SCN) is adapted to changes in the external environement by synchronization of its endogenous period with periodic changes of light and dark during day and night. The information about light travels via glutamatergic retinohypothalamic tract to the ventrolateral part of the SCN. Activation of ionotropic glutamate receptors in this area provably mediates the transfer of information about light on the transcriptional mechanism of light-sensitive cells. The role of the NMDA type of ionotropic glutamate receptors is well studied in this field and it is known that some NMDA receptor subunits show a circadian rhythm and an increased expression after a light pulse. Signalization via AMPA type receptors is much less elucidated. The aim of this thesis was to determine which AMPA receptor subunits are expressed in the SCN of the rat and if these subunits show a daily rhythm of expression and a reactivity to light pulse, as well as to outline the possible roles of distinct AMPA receptor subunits in the SCN. Keywords: circadian rhythms, suprachiasmatic nuclei, glutamate receptors, AMPA
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Synchronization of circadian system during prenatal and early postnatal development
Houdek, Pavel ; Sumová, Alena (advisor) ; Novotná, Růžena (referee)
One of the few attributes common to almost all living organisms is an ability to generate and maintain endogenous rhythms, which are controlled by a biological clock. The processes, which recur with a period of about 24 hours, are known as the circadian rhythms. The circadian clock controls rhythms of molecular, physiological as well as behavioral processes and adapts their activity to regularly appearing changes in day and night or season. In case of mammals, central oscillator is located in the hypothalamic suprachiasmatic nuclei (SCN). The SCN clock entrains rhythms of peripheral oscillators located in cells of other tissues. The central oscillator itself is synchronized with external environment mainly by a light-dark cycle, however, other cues can entrain the SCN clock as well. For example, during prenatal development, entrainment of a fetal clock is entirely dependent on non-photic cues derived from maternal organism. This study aimed to investigate a mechanism of the communication between the maternal and fetal central oscillators. A hypothesis was tested whether maternal melatonin may play a role in entrainment of the circadian clock in the fetal SCN. Furthermore, a mechanism, how melatonin may entrain the fetal clock was investigated at molecular level. The results provided evidence, that...
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Pineal lesions: clinical presentation, hormone secretion, sleep quality and effect of surgical treatment
Májovský, Martin ; Netuka, David (advisor) ; Šonka, Karel (referee) ; Lipina, Radim (referee)
Introduction: Pineal region is a deep-seated part of the brain surrounded by highly eloquent structures. Differential diagnosis of space-occupying lesions in this region encompasses pineal gland cysts, pineal gland tumours, metastases, germ cell tumours, meningiomas, gliomas, hemangioblastomas and neuroectodermal tumours. In this thesis, I focused mainly on patients with pineal cysts, which is a benign affection of the human pineal gland on the borderline between pathology and normality. The clinical management of patients with a pineal cyst remains controversial, especially when patients present with non-specific symptoms. A melatonin secretion in patients with a pineal cyst before and after a pineal cyst resection has not been studied yet and the effect of surgery on human metabolism is unknown. Materials and Methods: We performed a prospective study between 2000 and 2016. All patients with a pineal cyst larger than 7 mm were included. Epidemiological data, presenting symptoms, surgical results and radiographic and clinical follow-up were documented. We examined melatonin, cortisol and blood glucose secretion profiles perioperatively in a subgroup of 4 patients. The control group was represented by 3 asymptomatic patients with a pineal cyst. For each patient, 24-h circadian secretion curves of...
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