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Circadian clock in hippocampus
Šuchmanová, Karolína ; Sumová, Alena (advisor) ; Mareš, Pavel (referee)
Hippocampus is one of the main components of the limbic system. It plays an important role in the process of memory formation and recent literature shows that, like in other peripheral organs and brain structures, there is a circadian clock present in the hippocampus. The aim of the thesis was to study the hippocampal circadian clock under various conditions. The first part of the thesis examines the influence of glucocorticoid hormones on the clock gene expression in the hippocampus. Glucocorticoids are mammalian steroid hormones secreted from the adrenal glands that affect many processes in the organism. The glucocorticoid secretion is under the control of the circadian system, causing their levels to exhibit a pronounced diurnal rhythm. The hippocampus provides feedback to the hypothalamo-pituitary-adrenal (HPA) axis and is thus involved in the regulation of glucocorticoid hormone secretion. Hippocampal neurons also express glucocorticoid hormone receptors (GR). This thesis explores the effect of the absence of glucocorticoid hormones on the clock gene expression in the hippocampus. The absence of glucocorticoids was due to adrenalectomy and its effect was further compared with the effect of endogenous glucocorticoid replacement by daily injections of the GR agonist dexamethasone, emulating...
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Hippocampal neurogenesis in the adult brain and its changes in neuropsychiatric diseases
Brukhnová, Alena ; Kubová, Hana (advisor) ; Červená, Kateřina (referee)
The aim of my thesis is to summarize the information about neurogenesis in the dentate gyrus of the hippocampus in the adult brain. I examine the process of maturation, migration of immature neurons and functional significance of neurogenesis in the area. In the adult brain it is very important for proper spatial perception and learning. In the next chapter I focus on some significant neurodegenerative and neuropsychiatric diseases such as epilepsy, Alzheimer's disease or depression. During each of them leads to diverse changes and bnormalities in neurogenesis in hippocampal area. Powered by TCPDF (www.tcpdf.org)
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Circadian system and memmory
Skálová, Kateřina ; Bendová, Zdeňka (advisor) ; Houdek, Pavel (referee)
Circadian system is a part of all living organisms. It controls suitable timing of their physiological functions and behaviour. The molecular mechanism of interlocking transcription-translational feedback loops of clock genes and their protein products forms the core of the circadian system. The main structures of this system in mammalian organisms are suprachiasmatic nuclei of the hypothalamus. Memory is also closely connected with circadian system. It is one of the most important abilities of organism for creating knowledge. Both memory and circadian system enable to the organism to adapt to changes in its external environment. The expression of clock genes was detected in brain structures involved in mediation of memory such as hippocampus, amygdale and basal ganglia. The oscillations of these clock genes influence the formation and retrieval of memory traces. The aim of this work is to summarize current knowledge about the relationship between the memory and the circadian system. Key words: circadian system, memory, clock genes, suprachiasmatic nuclei, hippocampus
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Functions of the adult neurogenesis
Šejnová, Gabriela ; Stuchlík, Aleš (advisor) ; Melkes, Barbora (referee)
Neurogenesis in adult mammals was first discovered in the second half of the 20th century and its mechanisms, regulation and possible functions have been researched eversince. Scientists have so far been able to describe the process of neuronal development as well as some possible influences. However, the role of this phenomenon is still being discussed. This thesis is focused on neurogenesis in the dentate gyrus in hippocampus, a pair structure located in the central part of the temporal lobe. The main aim is to describe the recent findings and research models as well as the assumed functions. The most recent theories find the role of hippocampal neurogenesis in pattern separation, memory resolution, contextual memory or memory consolidation. These hypotheses are quite variable due to the broad range of research methods and their interpretations, however, none of them seems to disprove the others. Key words: neurogenesis, functions, behavior, hippocampus, learning
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Otimization of a dose of temozolomide for efficient reduction of adult neurogenesis in the laboratory rat
Pištíková, Adéla ; Stuchlík, Aleš (advisor) ; Jiruška, Přemysl (referee)
The goal of this study is to find an optimal dose of cytostatic Temozolomide (TMZ) for Long-Evans strain of rats. This dose should reduce neurogeneis while having a minimal pernicious health side-effects. Temozolomide is newly used to suppress neurogenesis but similarly to any other cytostatic has an effect on all dividing cells in an organism. This can affect health of an animal. Contrary to the mice, there was no systematic attempt to establish optimal dose. In our experiment rats were divided into four groups - one control group and three treatment groups which received different doses of temozolomide (10, 25, 40 mg/kg of TMZ). To detect level of neurogenesis cells were labeled by bromodeoxyuridine. During the experiment blood element counts were assessed, sensorimotoric tests were conducted, and weight increment was monitored. The results indicate that dose of 10mg/kg is adequate as it reduces neurogenesis by 64% compared to the control group and does not significantly differ from higher doses. In this group weight increment is comparable with the control group, while in the higher doses of TMZ weight increment is significantly lower. Effect of myelosupression is same for all treatment groups.
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Induction of neurogenesis and gliogenesis after ischemic CNS injury - the role of Wnt signaling pathway
Koleničová, Denisa ; Anděrová, Miroslava (advisor) ; Nerandžič, Vladimír (referee)
This bachelor thesis is focused on ischemic injury of the central nervous system (CNS), one of the most frequent causes of death and disability in the world, and its possible treatment via the induction of neurogenesis. It consists of three different parts. In the first part, main neurogenic regions of the CNS, the subventricular zone and gyrus dentatus (GD) of the hippocampus, are described at the cellular, as well as molecular level. The second part is mainly dedicated to ischemic injury, to the global and focal brain ischemia. A particular chapter of this part describes changes in neurogenesis and gliogenesis after ischemic injury of the brain, changes in the induction of radial glial cells, proliferation and migration of neural progenitor cells and neuroblasts. In this chapter, we also describe the activation of astrocytes, microglia and NG2 glia (also known as polydendrocytes) after ischemic injury of the CNS. The last, third part of the bachelor thesis, is focused on signaling pathways, which significantly influence neurogenesis: Shh (Sonic hedgehog homolog), Notch and Wnt (Wingles/Integrated) signaling pathways. Special attention is devoted to the Wnt signaling pathway, which is an essential part of molecular mechanisms in nerve cells. Keywords: neurogenesis, gliogenesis, hippocampus, gyrus...
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