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Influence of experimental intestinal dysbiosis on behavioral, neuroendocrine and immune properties of mice and the possibility of modifying it by administration of probiotic strain Escherichia coli O83:K24:H31
Avramová, Pavla ; Černý, Viktor (advisor) ; Roubalová, Radka (referee)
The gut microbiota is a key factor influencing the function of many organs in the human body, including the nervous, immune, and endocrine systems. This dynamic ecosystem can be modulated by diet, age, environment, even medication. The balanced composition of the microbiota is crucial for individual health, and its disruption leads to dysbiosis. The connection between the gut and the central nervous system is mediated by the microbiota-gut- brain axis. This axis consists of several pathways interconnected to mutually regulate their functions. Among the major components of the axis are the neural pathway, led by the vagus nerve, the immune pathway, and the endocrine pathway, including the HPA axis. Recent studies suggest that probiotic bacteria have the ability to partially rectify dysbiosis and alleviate its consequences for the organism. This thesis focuses on researching the impact of gastrointestinal tract microbiota on the behaviour, immunity, and neuroendocrine aspects of mice. It delves into experimentally inducing dysbiosis using antibiotics and subsequently addressing it with the probiotic bacterium Escherichia coli O83:K24:H31. The aim is to determine whether these probiotics can mitigate the adverse effects of dysbiosis on the immune and neuroendocrine systems, as well as behavioural...
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Epigenetic inheritance influencing the behavior of future generations and its reversibility during ontogenesis
Freisingerová, Kateřina ; Landová, Eva (advisor) ; Švorcová, Jana (referee)
The aim of this work is to focus on possible mechanisms of transmission of changes that are conditioned by epigenetic modifications that could affect specific behaviour and phenotype in offspring. The inheritance can be channeled through both maternal and paternal lineages. It can be divided into two distinct groups of transmission, namely intragenerational and transgenerational. This work mainly focuses on the possible mechanisms of transgenerational inheritance. Epigenetic mechanisms leading to changes in the phenotype of an organism rely on influencing the regulation of DNA reading. This occurs at several levels such as DNA methylation, chemical modifications such as acetylation and other post-translational modifications, and most importantly non-coding RNA molecules. Today, countless studies are trying to explain these molecular processes mediated by environmental influences. Well known are maternal care, chemicals, or traumatic experiences. There are examples of traumatic environmental influences in which physiological changes in HPA axis regulation can be observed with consequent changes in the expression of genes for depressive and anxiety phenotypes. Most of the experiments focusing on epigenetic transmission are predominantly conducted in mouse or rat models. However, there are also...
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Effect of stress on expression of 11β-hydroxysteroid dehydrogenase in rat brain
Kuželová, Andrea ; Pácha, Jiří (advisor) ; Vybíral, Stanislav (referee)
This thesis examines the influence of stress on the activity of hippocampal CA1 area. The main task was to determine whether the stress load affects the changes of the local metabolism of glucocorticoids, and whether the levels of corticosteroid receptors in the CA1 hippocampus are modulated in response to stress. In order to answer these questions, the experiments were carried out using three different rat strains - Fisher, Lewis and Wistar which differ in their activities of hypothalamic-pituitary-adrenal axis. Our results demonstrate that stress has no effect on expression of MR mRNA. Conversely, stress reduces the levels of GR mRNA in CA1 area of the dorsal hippocampus. Moreover, we confirmed that the Lewis and Wistar rats didn't change metabolism of glucocorticoids after stress response. By the Fisher rats increased levels of 11β-HSD1 mRNA expression and therefore increased the metabolism of corticosterone.
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Psychoneuroimmunology of alexithymia
Uher, Tomáš ; Bob, Petr (advisor) ; Boleloucký, Zdeněk (referee) ; Smolík, Petr (referee)
Alexithymia represents a deficit in identifying and expressing emotions, paucity of fantasies, and an externally oriented cognitive style. Currently, numerous studies document that alexithymia and several mental and somatic disorders are significantly related. Several findings also indicate that this association might be caused by alexithymia related dysregulation of neuroendocrine and immune functions. Together these findings indicate that stressors related to alexithymia could underlie the process of neuroendocrine and immune dysregulation that likely may present a significant risk, sustaining and mediating pathogenesis of several disorders and particulary psychosomatic illnesses. In this context, it is also known that several proinflammatory cytokines may play a role in pain generation and that alexithymia is significantly associated with pain symptoms in several pain disorders. Following these findings this study includes several new data developing current state of the art and showing some alexithymia specific changes in patients with neurological disorders. Main finding of this study shows that alexithymia and anxiety in their specific interactions are linked to increased levels of interleukine-8 (IL-8) in cerebrospinal fluid (CSF) in the group of patients with non-inflammatory neurological...
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The role of gut microbiota and HPA axis in childhood
Trunečková, Naděžda ; Kaňková, Šárka (advisor) ; Kreisinger, Jakub (referee)
The microbiota-host relationship is a complex system of interactions, which has evolved over thousands of years. Colonization of the gastrointestinal tract begins in prenatal period, continues after birth, and can be disrupted by different factors like a mode of delivery, lactation, or antibiotics. Main development of the intestinal microbiota and the central nervous system takes place in the first two or three years of life. The microbiota and the brain can mutually influence their development. For the communication is used the microbiota-gut-brain axis, which includes the neural, endocrine, metabolic and immunological pathways. Exposure to stress, whether in the prenatal period or in the first few years of life, can have a negative impact on the composition of the intestinal microbiota and the developing brain, including areas associated with the regulation of the HPA axis - one of the main mechanisms of stress regulation, which includes all interactions between the hypothalamus, pituitary gland and adrenal glands. Dysregulation of the microbiota-gut-brain axis can affect our response to stress, cognitive function, and emotions. The modified HPA axis response can affect our physical and mental health. It is associated with immune system disorders, behavioural disorders, social integration...
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Effect of microbiota on the activity of HPA axis
Fajstová, Alena ; Pácha, Jiří (advisor) ; Telenský, Petr (referee)
Recent research shows, that gut microbiome can influence various functions of the organism and is able to communicate with the brain. The data also show that changes in the composition of gut microbiome can influence behavior and stress reactions and vice versa, psychological state of the organism can cause changes in gut microbiome. The aim of this master's thesis was to examine changes of HPA activation and local metabolism of glucocorticoids caused by stress in the presence or absence of gut microbiome. We therefore used germ-free mice and studied the effect of stress in pituitary, adrenal gland, colon and spleen. We found that, stress has different impact on gene expression in adrenal gland, colon and spleen in the presence or absence of gut microbiome. In contrast, there wasn't any significant effect of stress on pituitary in germ free mice and their conventionaly colonized counterparts.
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Circadian regulation of glucocorticoid secretion
Tejkal, Karel ; Sumová, Alena (advisor) ; Soták, Matúš (referee)
Glucocorticoids belong to a family of steroid hormones synthesized in the adrenal gland. They fulfill a variety of functions related to metabolism, immune response and ontogenesis. Glucocorticoids function as the end-effector of hypothalamic-pituitary-adrenal (HPA) axis and as such, their levels in blood are elevated after exposure to stressors. The basal levels of glucocorticoid also show a pronounced diurnal rhythm, suggesting involvement of the circadian clock in the regulation of HPA axis. Studies have shown that other regulatory mechanisms apart from the HPA axis are involved in regulation of diurnal glucocortioid secretion. The disturbances of the regulatory mechanisms may lead to serious pathological conditions. This thesis describes the rhythmic nature of glucocorticoid release and mechanisms by which the circadian clock exerts its influence over the rhythm. Thereafter, the feedback of glucocorticoids onto the clock system is briefly explained. Finally, some examples of a role of abnormal glucocorticoid secretion in selected pathologies are provided.
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Effect of stress on expression of 11β-hydroxysteroid dehydrogenase in rat brain
Kuželová, Andrea ; Pácha, Jiří (advisor) ; Vybíral, Stanislav (referee)
This thesis examines the influence of stress on the activity of hippocampal CA1 area. The main task was to determine whether the stress load affects the changes of the local metabolism of glucocorticoids, and whether the levels of corticosteroid receptors in the CA1 hippocampus are modulated in response to stress. In order to answer these questions, the experiments were carried out using three different rat strains - Fisher, Lewis and Wistar which differ in their activities of hypothalamic-pituitary-adrenal axis. Our results demonstrate that stress has no effect on expression of MR mRNA. Conversely, stress reduces the levels of GR mRNA in CA1 area of the dorsal hippocampus. Moreover, we confirmed that the Lewis and Wistar rats didn't change metabolism of glucocorticoids after stress response. By the Fisher rats increased levels of 11β-HSD1 mRNA expression and therefore increased the metabolism of corticosterone.
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Psychoneuroimmunology of alexithymia
Uher, Tomáš ; Bob, Petr (advisor) ; Boleloucký, Zdeněk (referee) ; Smolík, Petr (referee)
Alexithymia represents a deficit in identifying and expressing emotions, paucity of fantasies, and an externally oriented cognitive style. Currently, numerous studies document that alexithymia and several mental and somatic disorders are significantly related. Several findings also indicate that this association might be caused by alexithymia related dysregulation of neuroendocrine and immune functions. Together these findings indicate that stressors related to alexithymia could underlie the process of neuroendocrine and immune dysregulation that likely may present a significant risk, sustaining and mediating pathogenesis of several disorders and particulary psychosomatic illnesses. In this context, it is also known that several proinflammatory cytokines may play a role in pain generation and that alexithymia is significantly associated with pain symptoms in several pain disorders. Following these findings this study includes several new data developing current state of the art and showing some alexithymia specific changes in patients with neurological disorders. Main finding of this study shows that alexithymia and anxiety in their specific interactions are linked to increased levels of interleukine-8 (IL-8) in cerebrospinal fluid (CSF) in the group of patients with non-inflammatory neurological...
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