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The role of striatal cholinergic signalling in the control of behaviour
Abbondanza, Alice ; Jakubík, Jan (advisor) ; Bellone, Camilla (referee) ; Svoboda, Jan (referee)
Cholinergic transmission regulates many behavioural domains, ranging from motor activity to cognition. Acetylcholine signalling is mediated by muscarinic and nicotinic acetylcholine receptors (mAChRs and nAChRs, respectively). While mAChRs are slow responding metabotropic receptors, nAChRs are ion channels, mediating fast neurotransmission. There is a growing body of evidence suggesting a role of nAChRs as important modulators of behavioural functions. However, as nAChRs consist of many subtypes, depending on their composition in subunits, and as they are expressed by various neuronal populations in different brain regions, their contribution to behavioural control is very complex. To decipher their contribution, it is necessary to selectively target nAChRs expressed not only in particular regions but also by particular neurons with a defined effect on local microcircuits. The goal of the present thesis was to use different genetic strategies to induce regional- and cell-specific deletion of β2-containing nAChRs in the mouse brain, in order to characterize the functional role of these receptors. We focused our work in two brain areas, the striatum and the prefrontal cortex (PFC). In the striatum, we identified the striatal neurons that express one of the most common nicotinic subunits, the β2...
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Stereological quantification of striatal NPY-positive interneurons and their genetic modification by the AAV5 viral vector
Smolík, Matyáš ; Janíčková, Helena (advisor) ; Chvojková, Markéta (referee)
Different types of interneurons in the striatum are still relatively poorly understood, especially compared to other parts of the brain such as the cortex or hippocampus. One of the lesser-known types of striatal interneurons that has received increasing attention recently, are neuropeptide Y-expressing interneurons (NPY+ interneurons). Available work indicates that these interneurons are controlled by striatal cholinergic interneurons and thus they may serve as mediators of cholinergic modulation in the striatum. The first aim of this thesis is to determine the absolute number of NPY+ interneurons in the mouse dorsal striatum by stereology, using a transgenic mouse model that shows GFP expression in NPY+ neurons. The second aim of this thesis is to use stereology to determine the volume of the dorsal striatum that we are able to target with viral expression when using a standard stereotactic injection protocol commonly used in our laboratory. The third aim of this study is to test the behavioural effect of knock down of the beta2 subunit of the nicotinic acetylcholine receptor expressed by NPY+ interneurons in the dorsal striatum. The work should serve as a first step in a study that will ultimately allow us to develop a quantitative idea of the absolute and relative number of NPY+ interneurons in...
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Gene expression pattern in the adult brain of the experimental rat after prenatal exposure to methamphetamine
Tomášková, Anežka ; Černá, Marie (advisor) ; Rudá, Jana (referee)
Introduction: Methamphetamine is a drug frequently taken by drug-addicted pregnant women and happens to be one of the most commonly used drugs in the Czech Republic. This drug passes easily through a placental barrier into the fetus. Thus it can negatively affect not only the mother but also the prenatal development of her offspring. Objectives: This research aims to provide a general screening of gene expression in selected regions of the F1 generation of the brain prenatally affected by methamphetamine, to verify whether exposure to methamphetamine affects the generation of offspring of exposed females at the level of gene expression in selected regions of the brain, and to valuate possible changes in gene expression. Methods: In selected parts of the brain, collected from a rat, the microarray hybridization and the real-time PCR were set to evaluate express changes in the expression of selected genes. Results: Statistical analysis of the microarray hybridization did not show a significantly altered gene expression in the tested genes. Only boundary values for 13 genes were measured, which were further tested by the real-time PCR. After a statistic evaluation of the real-time PCR, the significantly altered expression was found in 2 genes. The notably changed expression of DRD3 and TACR3 genes...
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Gene expression of specific parts of CNS in a rat model for transgenerational transmission of drug addiction.
Radilová, Kateřina ; Černá, Marie (advisor) ; Rothová, Olga (referee)
Methamphetamine (MA) is a drug often abused by drug-addicted women and also is the mostly used drug in the Czech Republic. This drug crosses the placental and hematoencephalic barriers easily and therefore it can negatively affect not just mother herself, but also the development of the fetus. Even though there have been several published studies evincive negative effects of MA to posterity of drug-addicted mothers, the most critical term during pregnancy for the fetus remains unknown. In this study are examined CNS structures, which are directly influenced by methamphetamine action. Their function may lead to drug addiction through pleasurable feelings, such as reward feeling evoking. In the next chapter are analysed neurotransmitters and their transporters, which are related to methamphetamine effects. Studying their structure, localization or development during life may help to bring near the drug functioning in different life periods. Methamphetamine itself and its effects are closer described in the last part of this study. The problem of methamphetamine exposed fetus is outlined there - prenatal and postnatal so far known differences, but also sex differences in methamphetamine pharma- cokinetics.
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Huntington's disease modeling and stem cell therapy in spinal cord disorders and injury
Hruška-Plocháň, Marián ; Motlík, Jan (advisor) ; Bjarkam, Carsten (referee) ; Roth, Jan (referee)
Neurological disorders affect more than 14% of the population worldwide and together with traumatic brain and spinal cord injuries represent major health, public and economic burden of the society. Incidence of inherited and idiopathic neurodegenerative disorders and acute CNS injuries is growing globally while neuroscience society is being challenged by numerous unanswered questions. Therefore, research of the CNS disorders is essential. Since animal models of the CNS diseases and injuries represent the key step in the conversion of the basic research to the clinics, we focused our work on generation of new animal models and on their use in pre-clinical research. We generated and characterized transgenic minipig model of Huntington's disease (HD) which represents the only successful establishment of a transgenic model of HD in minipig which should be valuable for testing of long term safety of HD therapeutics. Next, we crossed the well characterized R6/2 mouse HD model with the gad mouse model which lacks the expression of UCHL1 which led to results that support the theory of "protective" role of mutant huntingtin aggregates and suggest that UCHL1 function(s) may be affected in HD disturbing certain branches of Ubiquitin Proteasome System. Traumatic spinal cord injury and Amyotrophic Lateral...
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Porcine models for Huntington disease
Růna Vochozková, Petra ; Motlík, Jan (advisor) ; Bohačiaková, Dáša (referee) ; Fulková, Helena (referee)
The causative role of the huntingtin (HTT) gene in Huntington's disease (HD) has been identified more than 25 years ago. The extension of CAG repeat stretch over 39 repeats in exon 1 of one HTT allele results in full penetrance of this neurodegenerative disorder. While the identification of the causative mutation raised hopes that development of the therapeutic compound will be easily achievable, the patients and their families are still waiting for treatment until now. The main reason for that might be the complex cellular function HTT that makes the determination of the pathologic mechanism difficult and the development of treatments even more challenging. Although a lot of different animal models have been generated until now, establishing a suitable model has still not been achieved yet. Due to its anatomy, physiology, and genetics, the minipig seems to be a suitable candidate for neurodegenerative disease models. Indeed, the existing Transgenic (Tg) Libechov minipig model manifests signs typical for HD in patients, but on the other hand significant inconsistencies have also been observed. The finding of malformation that partially shows the situation in human patients is true for both, the male reproductive tract as well as for the brain. The reason for this might be the fact the genetic...
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Studying the role of striatal cholinergic signaling in control of behaviour and behavioural flexibility
Tyshkevich, Alexandra ; Janíčková, Helena (advisor) ; Levčík, David (referee)
Cognitive flexibility is an important mechanism enabling organisms to adapt to their changing environment. Different brain structures are involved in this complex process. It has been repeatedly shown that the striatum is one of the key structures controlling cognitive flexibility. Striatum receives rich input from different brain regions while its output is rather uniform. Striatal functions and signalling are greatly modulated by dopamine and acetylcholine. A number of studies have shown involvement of striatal acetylcholine and its receptors in the control of cognitive flexibility but very little is known about the role of M4 muscarinic acetylcholine receptors. These receptors are inhibitory, and they have been shown to induce long-term depression in striatal medium spiny neurons, therefore opposing the action of the dopamine D1 receptors. We hypothesize that the inhibitory effect of M4 muscarinic acetylcholine receptors may supress spiny projection neurons coding for outdated and no longer effective behavioural strategy and thus they may be necessary for the flexible change of behaviour. In the present thesis, I investigated the effects of pharmacological antagonism of M4 receptors on cognitive flexibility of mice tested in a simple reversal learning paradigm. Key words: striatum; cholinergic...
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Modelovanie ochorenia a štúdium regeneračných procesov v Huntingtonovej chorobe a ALS in vivo
Hruška-Plocháň, Marián
Neurological disorders affect more than 14% of the population worldwide and together with traumatic brain and spinal cord injuries represent major health, public and economic burden of the society. Incidence of inherited and idiopathic neurodegenerative disorders and acute CNS injuries is growing globally while neuroscience society is being challenged by numerous unanswered questions. Therefore, research of the CNS disorders is essential. Since animal models of the CNS diseases and injuries represent the key step in the conversion of the basic research to the clinics, we focused our work on generation of new animal models and on their use in pre-clinical research. We generated and characterized transgenic minipig model of Huntington's disease (HD) which represents the only successful establishment of a transgenic model of HD in minipig which should be valuable for testing of long term safety of HD therapeutics. Next, we crossed the well characterized R6/2 mouse HD model with the gad mouse model which lacks the expression of UCHL1 which led to results that support the theory of "protective" role of mutant huntingtin aggregates and suggest that UCHL1 function(s) may be affected in HD disturbing certain branches of Ubiquitin Proteasome System. Traumatic spinal cord injury and Amyotrophic Lateral...
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Cholinergic signaling in the striatum and its significance in cognitive flexibility
Smolík, Matyáš ; Janíčková, Helena (advisor) ; Funda, Jiří (referee)
In the striatum, cholinergic interneurons (CINs) contribute to the control of behaviour, motor and cognitive functions. Recently, number of studies have shown a special significance of CINs in the control of cognitive flexibility: the ability to learn new behavioural strategies when requirements of the environment change. Along with working memory, cognitive inhibition, attention control and other cognitive domains, cognitive flexibility belongs to executive functions. Cognitive flexibility impairment is present in a range of neuropsychiatric disorders and thus, understanding its mechanisms is of outstanding importance. The proposed work will first describe anatomy and cellular composition of the striatum and its functions. It will further describe cholinergic system with a special attention to cholinergic signalling in the striatum. The final chapter of the general part of the thesis will focus on cognitive flexibility. After discussing the involved structures and systems separately, the thesis will eventually provide comprehensive review of currently available studies investigating how striatal CINs contribute to brain's ability to replace old concepts with new and more efficient ones.
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Porcine models for Huntington disease
Růna Vochozková, Petra ; Motlík, Jan (advisor) ; Bohačiaková, Dáša (referee) ; Fulková, Helena (referee)
The causative role of the huntingtin (HTT) gene in Huntington's disease (HD) has been identified more than 25 years ago. The extension of CAG repeat stretch over 39 repeats in exon 1 of one HTT allele results in full penetrance of this neurodegenerative disorder. While the identification of the causative mutation raised hopes that development of the therapeutic compound will be easily achievable, the patients and their families are still waiting for treatment until now. The main reason for that might be the complex cellular function HTT that makes the determination of the pathologic mechanism difficult and the development of treatments even more challenging. Although a lot of different animal models have been generated until now, establishing a suitable model has still not been achieved yet. Due to its anatomy, physiology, and genetics, the minipig seems to be a suitable candidate for neurodegenerative disease models. Indeed, the existing Transgenic (Tg) Libechov minipig model manifests signs typical for HD in patients, but on the other hand significant inconsistencies have also been observed. The finding of malformation that partially shows the situation in human patients is true for both, the male reproductive tract as well as for the brain. The reason for this might be the fact the genetic...
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