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Adult neurogenesis in the hippocampus and spatial navigation
Dostálová, Magdalena ; Stuchlík, Aleš (advisor) ; Jiruška, Přemysl (referee)
Hundreds to thousands of new granule neurons are born every day in the hippocampus within the whole life. Inspite of intensive research of the last decades, their function remains unclear. Their participation in spatial memory and the ability of orientation is assumed. Results from behavioral tests like the Morris water maze, the radial maze and many other testing tasks, are often contradictory. Nevertheless, it is highly probable that neurogenesis plays a role in pattern separation and long-term relational memory. Further studies and especially reliable methods of ablation and detection are required for deeper insight into this issue.
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Differentiation potential of polydendrocytes after focal cerebral ischemia
Filipová, Marcela ; Anděrová, Miroslava (advisor) ; Jendelová, Pavla (referee)
Ischemic injury leeds to sequence of pathophysiological events, which are accompanied by a release of growth factors and morphogens that significantly affect cell proliferation, migration and also their differentiation. Following ischemia, besides enhanced neurogenesis and gliogenesis in subventricular zone of the lateral ventricles and gyrus dentatus of the hippocampus, neurogenesis/gliogenesis also occurs in non-neurogenic regions, such as cortex or striatum. Recently, the attention was turned to a new glial cell type, termed polydendrocytes or NG2 glia. Under physiological conditions, these cells are able to divide and differentiate into mature oligodendrocytes due to they have often been equated with oligodendrocyte precursor cells. Based on recent reports, polydendrocytes are also able to generate protoplasmic astrocytes (Zhu et al., 2008) and neurons in vitro (Belachew et al., 2003), however their ability to differentiate into astrocytes or neurons under physiological or pathological conditions is still highly debated. Therefore, we have investigated the effect of different growth factors and morphogens, specifically brain-derived neurotrophic factor (BDNF), basic fibroblast growth factor (bFGF), vascular endothelial growth factor (VEGF) and a morphogen sonic hedgehog (Shh), on...
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Neurogenesis in the adult brain, its regulation and possible functions
Pištíková, Adéla ; Stuchlík, Aleš (advisor) ; Jiruška, Přemysl (referee)
In this thesis I examine neurogenesis in the adult brain. Neurogenesis takes place in two main neurogenic areas. One area is located at the side of the forebrain ventricle and the other in dentate gyrus of the hippocampus. The forebrain ventricle neurogenesis is important for olfactory discrimination and olfactory memory. In the hippocampus, its function is unclear, but there are several hypotheses about its possible significance. We assume it might function in pattern separation and also be involvedin preventing interference between memory traces. The last chapter I dedicate to the positive and negative regulation of neurogenesis. The manipulations enhancing neurogenesis include voluntary physical activity, enriched environment and SSRI antidepressants. The negative impact on neurogenesis is exerted among other factors by stress, irradiation and a cytostatic Temodal, which is used methodologiclly to block neurogenesis.
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Induction of neurogenesis and gliogenesis after ischemic injury of CNS
Filipová, Marcela ; Moravec, Jan (referee) ; Anděrová, Miroslava (advisor)
Ischemic injury (stroke) is one of the most common causes of death and disability in humans. Discovery of adult neurogenesis and possibilities to induce neurogenesis by cytokines brought new approaches and hopes in treating the ischemic lesion in future. The aim of this thesis is to describe cellular and molecular mechanisms of neurogenesis, mainly those discovered within last ten years. The first part describes generation of new neurons in the brain under physiological conditions, which is localized in the dentate gyrus of the hippocampus and in the subventricular zone of the lateral ventricles (i.e. in principal neurogenic regions). The second part describes animal models used for studying ischemic injury in rodents and moreover, it focuses on patophysiology of ischemic brain injury, which is accompanied by astrocyte and microglia activation. Further, the ischemia-induced neurogenesis is described in these two major neurogenic regions. Also the important role of NG2 glial cells in central nervous system (CNS) regeneration is pointed out. According to recent findings NG2 glia that are present in all regions of CNS might serve as a potential source of cells for directed differentiation into oligodendrocytes, astrocytes and even neurons during CNS repair/regeneration. In the last part of this work,...
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