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Development of callosal interhemispheric connection in laboratory rat
Matternová, Lucie ; Mareš, Pavel (advisor) ; Žiak, Jakub (referee)
Corpus callosum is the main commissure linking cortex of the right and left brain hemisphere. For the first time, the callosal axons are observed during E18, when they cross the midline. In PND 5, most axons reach the contralateral cortex, and at the end of the second postnatal week, the callosal projection neurons and axon terminals are located similarly to the adult animal. The interhemispheric response was first observed in the rat in PND 4 but myelination in PND 12, suggesting that the transcallosal response is not dependent on myelinization of callosal fibers. As the rat age increases, the wave duration of the TCR, latency peak and threshold decreases. As opposed to that, amplitude of the positive and negative wave increases with age. TCR may be affected by acute drug application or chronic exposure to various effects, such as hormones.
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The effect of cold exposure on beta-adrenegic signaling in the rat myocardium
Podojilová, Anna ; Novotný, Jiří (advisor) ; Ujčíková, Hana (referee)
and keywords The aim of this work was to evaluate the effect on rat myocardial β-adrenergic system of short-term (10 hours and 3 days) and long-term (5 weeks) cold exposure of rats with possible subsequent two-week recovery at normal temperature. The subtypes of β-adrenergic receptors (β-AR), their cognate G-proteins and adenylate cyclase have been characterized. β-AR are important components of cardiac regulatory mechanisms. They are involved in stimulating G-protein (Gs) and adenylate cyclase to increase cardiac contractility and frequency during stressful situations, including cold exposure. Heart tissue contains all three β-AR subtypes (β1-AR, β2-AR, β3-AR). While β1-AR couples with only Gs, β2-AR and β3-AR interact with the inhibitory G-protein (Gi). Electrophoresis and Western blotting showed a significant increase in β1-AR after a three-day exposure to cold. There was also a significant increase in β3-AR concentrations after a five-week cold exposure and this increase lasted for two weeks. There were no significant changes in the amnounts of β-AR cognate G-proteins (Gαs, Gβ, Gαi1/2 a Gαi3). In contrast, expression of adenylyl cyclase isoform V and VI significantly decreased during short-term exposure to cold. Using the saturation experiment with the β-antagonist [3H]CGP 12177, β-AR were...
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Neurobehavioral consequences of experimental psychosis in laboratory rats
Svojanovská, Markéta ; Stuchlík, Aleš (advisor) ; Telenský, Petr (referee)
Schizophrenia is a serious neuropsychiatric disease with a lifetime prevalence of 1% and it disrupts almost all mental functions. It manifests with many symptoms, which can be roughly classified into three main classes - positive, negative and cognitive dysfunctions. The psychosis, which can be often seen in schizophrenia, is a very serious problem that along with all other symptoms influences the patients' clinical status as well as quality of their life. As no direct causes or causal treatments for schizophrenia are known, scientist often focus on animal models of schizophrenia as tools for investigating mechanisms that can take a part in real disease and for seeking novel antipsychotics. This thesis aims at investigating two-week subchronic treatment with dizocilpine (MK-801), a non-competitive antagonist of NMDA receptors, in Wistar and Long-Evans rats aged 30 (PND 30) and 60 days (PND 60) at the onset of the treatment. Subsequently, long-term neurobehavioral consequences of this experimental psychosis were studied by testing rats at three behavioral tasks: the Elevated-plus maze (EPM), the Morris water maze (MWM) and active place avoidance on a rotating arena (Carousel). The Western blot method was used to determine post-mortem changes in expression of the NR1, NR2A and NR2B subunits of the...
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Mnemonic and behavioural effects of biperiden, an M1-selective antagonist, in the rat
Popelíková, Anna ; Stuchlík, Aleš (advisor) ; Telenský, Petr (referee)
Due to the persisting lack of reliable animal models of cognitive impairment with good translational validity, researches strive to discover new ways and tools to replicate symptoms of human neurodegenerative diseases in rodents. Recently, biperiden, an M1- selective muscarinic antagonist, has been proposed as a potential tool for generating fast screening models of mnemonic deficits such as seen in patients with Alzheimer's disease. Being highly selective for the M1 receptor, a predominant type of muscarinic acetylcholine receptors in the brain involved in cognitive processes, it has been speculated to possibly only influence cognition without causing sensorimotor side effects. Studies assessing the usability of this drug reported conflicting results. We have decided to expand the experimental data and evaluate biperiden's validity in several variants of the Morris water maze. The results of this study showed no significant effect of biperiden on cognitive flexibility, tested by reversal learning. In delayed-matching-to-position paradigm, which tests assesses working memory, we found a difference in performance between the two experimental groups; however, it cannot be unequivocally attributed to a memory impairment. No effects were observed in visible platform task, confirming a lack of...
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Vliv klomipraminu a risperidonu na učení a flexibilitu u animálního modelu obsedantně kompulzivní poruchy
Radostová, Dominika ; Stuchlík, Aleš (advisor) ; Kopřivová, Jana (referee)
Chronic sensitization of dopamine D2/D3 receptors by agonist quinpirole (QNP) induces compulsive checking behaviour in rats, which is considered an animal model of obsessive-compulsive disorder (OCD). Previous study revealed deficit in cognitive flexibility in QNP sensitized rats. This thesis focused on determining if this cognitive flexibility deficit is ameliorated by co-administration of clomipramine (CMI), risperidone (RIS) or combination of both (CMI+RIS) to QNP treatment. Aversively motivated active place avoidance task on a Carousel maze with reversal was used. The number of entrances into a to-be-avoided shock sector was evaluated as measure of performance. Six treatment groups were used: control group, QNP group, CMI group, QNP/CMI combination, QNP/RIS combination and QNP/CMI/RIS combination. Surprisingly, when compared alone, significantly worse acquisition was observed for QNP group compared to control group. However, similarly to previous study, QNP group had a worse performance in a first reversal session compared to control group. When all groups were compared, only QNP/CMI group had worse initial learning compared to control group. In reversal learning, only QNP treated group had a significantly more entrances than control group in first reversal session. Results suggest that co-treatment...
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Mitochondrial respiration at cold acclimated rats. Comparison of tissues.
Flégrová, Eliška ; Žurmanová, Jitka (advisor) ; Nováková, Olga (referee)
Acclimation to cold or hardening is known for many decades through its beneficial effects on human health. In contrast, sudden exposure to cold, cold shock, is a great risk of cerebral and cardiac injury, especially in the elderly. There is very little published data on the cellular and molecular mechanisms induced by cold adaptation in heart and brain. The aim of this work was to describe and compare different properties heart, liver, brain and brown adipose tissue mitochondria of rats housed at 25 ± 1 řC and at mild cold (9 ± 1 řC, 5 weeks). The high-resolution oxygraphy, spectrophotometry and Western blotting analyses were used. We found differences in the respiratory control between the heart and liver. Cold acclimation decreased activity of the Krebs cycle enzymes. Fatty acid contribution to the respiration reached the maximum in brown fat and the minimum in the hippocampus. However, further study is necessary.
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Genetic determination of cholesterolemia regulation
Vlachová, Miluše ; Kovář, Jan (advisor) ; Vrablík, Michal (referee) ; Kazdová, Ludmila (referee)
Most types of hypercholesterolemia are of polygenic origin. Some genes related to hypercholesterolemia are known, although all genes responsible for cholesterolemia regulation have not been characterised yet. To identify these new genes, animal models with spontaneous defects in cholesterol metabolism could be very useful. Moreover, a number of variations and polymorphisms have been found to influence blood cholesterol levels in humans. Some may also affect cholesterolemia responsiveness to dietary fat. The Prague hereditary hypercholesterolemic (PHHC) rat is a unique model of hypercholesterolemia induced by dietary cholesterol alone (without administration of cholic acid or thyrotoxic drugs). It exhibits modestly increased cholesterolemia when fed chow and responds to a diet containing cholesterol with a several-fold increase of cholesterolemia to concentrations comparable to those observed in hypercholesterolemic patients. Hypercholesterolemia in this model is characterised by accumulation of very low density lipoproteins (VLDL) and intermediate density lipoproteins (IDL) enriched by cholesterol. In an experiment with tyloxapol (an inhibitor of lipoprotein lipase) we found that PHHC rats on a cholesterol diet incorporated twice as much cholesterol into VLDL as Wistar rats, although liver...
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Model of cerebral focal cortical ischemia and its parametrization
Svoboda, Jan ; Otáhal, Jakub (advisor) ; Konopková, Renata (referee)
Title of work: Model of cerebral focal cortical ischemia and its parametrization Work objectives: The aim of this diploma thesis was to apply modified model of focal cortical brain ischemia induced by phototrombosis and subsequently determinate its parameters. Methods: Intravenous application of photosensitive Rose Bengal dye was followed by continual illumination of green laser beam over the left sensorimotocortex for 10 minutes. Following illumination, the dye is activated and produces singlet oxygen that damages components of endothelial cell membranes, with subsequent platelet aggregation and thrombin formation, which eventually determines the interruption of local blood flow. This approach, initially proposed by Rosenblum and El-Sabban in 1977, was later improved by Watson in 1985 in rat brain. For histological evaluation of ischemic brain damage, animals were overdosed with urethane and transcardially perfused. Results: Histological examination of brains showed significant ischemic damage in all experimental animals. Lesion was located in left hemisphere and penetrated thought the grey matter in various extents. Size of lesion, its localization and depth has shown only a small variability in the individual groups. Noticeable differences were found right after comparing experimental groups....
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Curcumin in the treatment of traumatic spinal cord injury
Kloudová, Anna ; Machová Urdzíková, Lucia (advisor) ; Martončíková, Marcela (referee)
Spinal cord injury is a very significant clinical as well as social problem with extensive consequences, affecting the patient and also his/her family. Great efforts have been devoted to searching for an effective treatment, which would improve their situation. This thesis evaluated the effects of the natural compound curcumin on spinal cord injury using an experimental balloon compression model. Male Wistar rats were randomized into two groups following the lesion induction, namely vehicle- or curcumin-treated. The behavioral recovery was evaluated using a set of locomotor and sensory tests and a histological and imunohistochemical analysis was performed. The qPCR method was used to observe the expression of some genes related to regeneration and immune response. It was demonstrated that curcumin improved locomotor recovery after the spinal cord injury, particularly in the early stages. Morphometric analysis of the gray and white matter sparing didn't confirm any differences between the two groups. Nevertheless, the glial scar formation was significantly reduced around the central part of the lesion in the curcumin treated group and also the NF-κB activity was substantially inhibited. The gene expression analysis demontrated downregulation of Gfap and Rantes genes and upregulation of the Irf5 gene...
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Influencing motor activity in laboratory rat offspring by specific antagonist of AMPA receptors.
Soukupová, Andrea ; Mareš, Pavel (advisor) ; Valeš, Karel (referee)
The IEM 1460 is a potential age-specific anticonvulsant and an indicator of the distribution of AMPA receptor subtypes among rat brain cells. It is a derivative of adamantane, that was tested in previous studies on models of human myoclonic and generalized tonic-clonic seizures with promising results. In this thesis we evaluated its effect on the motor activity of rat offspring in the age of 12, 18 and 25 days, we used 90 animals in total . The effect was evaluated 30 minutes after intraperitoneal administration of IEM 1460 in two doses, 10 mg/kg or 20 mg/kg, and was compared to the control animals with physiological solution applied intraperitoneally in amount of 20 mg/kg. To test the animals we used Open field test, righting reflex, negative geotaxis, horizontal bar test, rope climbing test, regular and irregular horizontal ladder test. The tests were applied to animals in mentioned order. There were found significant changes influencing motor behaviour, primarily in the 12 days old animals with the dose of 20 mg/kg IEM 1460 and in the 25 days old animals with both doses of IEM 1460, 10 and 20 mg/kg. In the 18 days old animals the results were less significant. Powered by TCPDF (www.tcpdf.org)
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