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Development of photic entrainment of the circadian clock of the rat during early postnatal ontogenesis
Matějů, Kristýna ; Sumová, Alena (advisor) ; Höschl, Cyril (referee) ; Langmeier, Miloš (referee) ; Nevšímalová, Soňa (referee)
In most organisms, behavioral and physiological events oscillate with period ± 24 h, i.e. exhibit circadian rhythms. In mammals, circadian rhythms are generated by circadian clock within the suprachiasmatic nuclei of the hypothalamus (SCN). Light entrains circadian rhythms to the 24 h period of solar day. Information about light is conveyed from the retina to the SCN and induces expression of clock genes Period1 (Per1) and Period2 (Per2) that represent photosensitive parts of molecular circadian clockwork within SCN. Light sensitivity of Per1 and Per2 within SCN is temporally restricted to the subjective night phase. In addition, daily profiles of clock gene expression within SCN are modulated by daylenght, i. e. the photoperiod. The aim of our study was to elucidate how the mechanism of photic entrainment of the rat circadian clock develops during prenatal and early postnatal ontogenesis. Our results demonstrate that maternal circadian system provides information about external light to the fetal and early postnatal circadian clock. Circadian clock within the SCN of rat pups is light sensitive already at the first postnatal day. Mechanism gating the light sensitivity is present at postnatal day 3 and gradually maturates until postnatal day 10. The data suggest that the developing retina is responsive to...
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The role of transmembrane domains in the structure and function of P2X receptors
Jindřichová, Marie ; Zemková, Hana (advisor) ; Langmeier, Miloš (referee) ; Martásek, Pavel (referee)
Purinergic P2X receptors represent a novel structural type of ligand-gated ion channels activated by extracellular ATP. So far, seven P2X receptor subunits have been found in excitable as well as non-excitable tissues. In the past ten years, the number of studies on P2X receptors has dramatically increased as investigators have begun to determine the physiological roles played by extracellular ATP and specific P2X receptor subtypes. It is already known that purinergic signaling is a key mechanism in pain sensation, brain injury, and immune processes. Little is known about their structure, mechanism of channel opening, localization and termination of ATP action by ectonucleotidases. Detailed knowledge about these events and the structure of purinergic receptor proteins evoke hope that new drugs will be developed that could prevent chronic pain and would be effective in protection against many diseases. The aim of this work is to summarize recent investigations and describe our contribution to elucidating the structure of P2X receptors. We examined the structure of transmembrane domains of the P2X4 receptor subtype, the main purinergic receptor-channel in the central nervous system, the mechanism of channel opening and closing and its sensitivity to agonists and allosteric modulator ivermectin. To...
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název v anglickém jazyce není uveden
Benešová, Petra ; Langmeier, Miloš (advisor) ; Hach, Petr (referee) ; Kozler, Petr (referee)
Using hislochemical analysis (NADPH-diaphorase) we have been investigating the influence of intraperitoneal administration of kainic acid, hypoxia and combination of both these factors on neurons of the hippocampus and on the primary auditory cortex in male rats of the Wistar strain. Kainic acid was administered to 12-day-old and I8-day-old animals, which were exposed to long-lasting repeated hypoxia from the 2nd till the 17th day of age in a hypobaric chamber (for 8 hours a day). At the age of 22, 90 and 365 days, the animals were transcardially perfused with 4% paraformaldehyde under deep thiopental anesthesia. Cryostate sections were stained to identify NADPH-d positive neurons that were then quantified in CA1 and CA3 areas of the hippocampus, in the hilus, dorsal and ventral blade of the dentate gyrus and in the primary auditory cortex. In 22-day-old animals with kainic acid administered 18th day of life both hypoxia and kainic acid increased the number of NADPH-d positive neurons in the hilus, CA1 and CA3 areas of the hippocampus and in the primary auditory cortex. On the contrary, kainic acid given to the hypoxic animals lowered the number of NADPH-d positive neurons in the dentate gyrus. In 90-day-old animals with kainic acid administered 18th day of life hypoxia and kainic acid given to both,...
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název v anglickém jazyce není uveden
Glogarová, Kateřina ; Syková, Eva (advisor) ; Langmeier, Miloš (referee) ; Rokyta, Richard (referee)
Magnetic resonance imaging (MRI) provides a useful noninvasive method to study the long-term migration and fate of transplanted stem cells in the central nervous system in vivo. Grafted adult as well as embryonic stem cells (ESCs) labeled with superparamagnetic nanoparticles survive in the host organism and migrate preferentially into a lesion site, where they populate the damaged nervous tissue. The migration is not affected by the route of administration; the lesion is populated with the same number of cells after intracerebral grafting as after intravenous injection. Less than 3 % of transplanted mesenchymal stem cells (MSCs) in a cortical photochemical lesion differentiated into neurons and none into astrocytes, while most ESCs (70 %) differentiated into astrocytes and only 5 % into neurons. The intravenous injection of MSCs or of the mononuclear fraction of the bone marrow, which includes hematopoietic and nonhematopoietic stem cells, progenitors and lymphocytes (BMCs), as well as the mobilization of endogenous BMCs with G-CSF (granulocyte colony stimulating factor) significantly improved the recovery of hind limb motor function and sensitivity in rats with a spinal cord compression lesion and significantly increased the spared white matter volume in the center of the lesion. The recovery was most...
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G peoteins and adenylyl cyclase during onhogenetic development of rat brain cortex
Stohr, Jiří ; Svoboda, Petr (advisor) ; Langmeier, Miloš (referee) ; Mareš, Pavel (referee)
CONCLUSIONS our measurementsof agonist.stimulatedhigh-affiniý GTPase activiý and GTftS binding in thedevelopingrat brain cortexhaverevealeda markedlyhigherfunctionalactivity of GTP.binďng proteins in adult (9O{ay.old) than in immaturate(12day.o1d) ťaB.This study further demonsbatesthat RGSI, by contrast to RGSI6, might function as srong regulatorofhigh-afiiniý GTPase activity in this tissue. AC activity is regulatedsimilarly in brain cortex from immaturateand adult rats,but theenzymeactivity is much lower in adultthanin immaturateanimals.As arguedpreviously, the ďfference betweenAc actiúty in thesetwo agegroups is not explicable on the basis of the dwelopmental expressionprofiles of either ACl, ACz, AC4 and AC6 or ďfferent G proteins(Ihnatorrychet a1.,2@2a;Ihnatov.vchetal.,2002b).Itmightbe speculated,however, that the complement of some other types of AC could gg slanged in adulthood. This supposition is supportedby our recent finding of altered characteristicsof [3H]forskolin binding in cerebrocorticalmembranesfrom adult comparedto imÍraturaterats (Stóhr et al., 2005b)-Nevertheless,a possibilitycan not be ruled out thatAC activityin adultrat brain cortex might be perhaps affected by some yet not known negative regulatory factor/mechanism,which is switchedon shortlyaftermaturation. That high-afÍiniý as well...
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Postnatal development of GABAb-receptors in the frontal rat brain cortex
Kagan, Dmytro ; Svoboda, Petr (advisor) ; Langmeier, Miloš (referee) ; Mareš, Pavel (referee)
In this work, the detailed analysis of GABAB-R/G protein coupling in the course of pre- and postnatal development of rat brain cortex indicated the significant intrinsic efficacy of GABAB-receptors already shortly after the birth: at postnatal day 1 and 2. Subsequently, both baclofen and SKF97541-stimulated G protein activity, measured as the high-affinity [35 S]GTPγS binding, was increased. The highest level of agonist-stimulated [35 S]GTPγS binding was detected at postnatal days 14 and 15. In older rats, the efficacy, i.e. the maximum response of baclofen- and SKF97541-stimulated [35 S]GTPγS binding was continuously decreased so, that the level in adult, 90-days old rats was not different from that in newborn animals. The potency of G protein response to baclofen stimulation, characterized by EC50 values, was also high at birth but unchanged by further development. The individual variance among the agonists was observed in this respect, as the potency of SKF97541 response was decreased when compared in 2-days old and adult rats. The highest plasma membrane density of GABAB-R, determined by saturation binding assay with specific antagonist [3 H]CGP54626AA, was observed in 1-day old animals. The further development was reflected in decrease of receptor number. The adult level was ≈3- fold lower than...
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Clinical findings and diagnosis of vestibular lesions in patiens with vestibular schwannomem
Kalitová, Petra ; Langmeier, Miloš (advisor) ; Šlapák, Ivo (referee) ; Kozler, Petr (referee)
Summary: The aim of our study was diagnosis and rehabilitation of vestibular loss in patients with vestibular schwannoma. In the first part we focused on analysis of a group of patients before resection of vestibular schwannoma, mainly on evaluation of gain of posturography and on optimalisation of diagnostic algorithm of vestibular pathology. Throughout the second experiment, we studied if rehabilitation of postural gait with visual biofeedback will speed up vestibular compensation in patients after resection of vestibular schwannoma. The group consisted of 44 patients, who underwent surgical removal of vestibular schwannoma. Before surgery each patient underwent clinical vestibular examination, electronystagmographic recordings and posturography. In the second part of the study 17 patients from previous group were chosen. These patients underwent rehabilitation and rehabilitation with biofeedback. For evaluation was used independent samples T-test and cross-tabulation. A great number of variables were reduced by factor analysis. For statistical analysis of the group with rehabilitation was used nonparametric Wilcoxon signed rank test. Statistical analysis revealed that the most typical parameter for vestibular pathology is the time of the step quick turn test, which is a part of posturography. We proved...
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název v anglickém jazyce není uveden
Milotová, Martina ; Langmeier, Miloš (advisor) ; Kozler, Petr (referee) ; Stárka, Luboslav (referee)
The long-term consumption of ethanol by pregnant or nursing rat mothers results in extensive damage of the hippocampal area in their offspring. The histochemical methods combining bis-benzimide 33342 (Hoechst) and Fluoro-Jade B staining were used to detect ethanol effects on the structure of the rat hippocampus and gyrus dentatus during development and adult age (18, 35, 90 and 360 days old offspring). In all experimental groups, in all analyzed areas, degenerative changes were observed, loss of pyramidal and granular cells and neural cells with segmented nuclei. In animals, whose mothers drunk 20% ethanol, structural changes were more intensive when compared with the group consuming 10% ethanol. The highest density of the degenerating (FJ/B positive) cells was found in 18-days-old animals whose mothers were exposed to 20% ethanol. In the age of 90 and 360 days no degenerating cells were identified in the monitored areas. With respect to the properties of the ethanol and mechanism of its effect we suppose that exposure to ethanol during the perinatal period induced the neural cell loss by apoptotic mechanism. From the results of the work can be concluded: 1. The perinatal exposure to ethanol results in degeneration of neural cells in the hippocampus and gyrus dentatus (working hypothesis I was confirmed)....
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The role of the immune response in the pathophysiology of infectious meningitis
Beran, Ondřej ; Holub, Michal (advisor) ; Bartošová, Drahomíra (referee) ; Langmeier, Miloš (referee)
CNS infections continue to be associated with a high morbidity and mortality. Thus, it is neccessary to improve current diagnostic and therapeutical approaches. Better understanding to the pathophysiology of CNS infections is crucial for this process. In this thesis, the results of 4 clinical studies and 1 experimental study were presented. The overall aim of the studies was to expand knowledge about the immunopathophysiology of infectious meningitis (IM). For this purpose, we analysed several parameters of cellular immunity, cytokine production and activation of endogenous endocrine response during IM. Also, a potential use of new biomarkers in differential diagnostics of IM was evaluated. The results documented that the immune response during acute bacterial meningitis (BM) as well as aseptic meningitis (AM) is compartmentalized to the CNS. The most important changes take place in the subarachnoideal space; however, several alterations of the innate and adaptive immunity were found in peripheral blood as well. Novel findings observed in our studies are as follows: The presense of activated macrophages (HLA-DR+) is associated with a favorable outcome of in patients with BM. In patients with BM, a high inflammatory response in the CNS which is associated with elevated cytokine and chemokine...
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Induction of neuronal cell death by neurotoxin factors
Riljak, Vladimír ; Langmeier, Miloš (advisor) ; Kozler, Petr (referee) ; Herink, Josef (referee)
Using histochemical analysis (NADPH-diaphorase, Fluoro-Jade В dye and bisbenzimide 33342 Hoechst) we studied the influence of intraperitoneal administration of nicotine, kainic acid and combination of both these substances on hippocampal neurons and their changes. In experiments, 18- 25- and 35-day-old male rats of the Wistar strain were used. 30 minutes prior to the kainic acid application (10 mg/kg), animals were pre-treated with 1 mg/kg of nicotine. After 2 days, the animals were transcardially perfused with 4% paraformaldehyde under deep thiopental anaesthesia. Cryostat sections were stained to identify NADPH-diaphorase positive neurons that were then quantified in the CA1 and CA3 areas of the hippocampus, in the dorsal and ventral blades of the dentate gyrus and in the hilus of the dentate gyrus. Fluoro-Jade В positive cells were examined, in the same areas, to elucidate possibly neurodegeneration. Results have shown that nicotine administration brings about the increase of the density of NADPH-diaphorase positive neurons in CA1 and CA3 areas of the hippocampus and in the hilus of the dentate gyrus in 18-day-old animals, in 25-dayold animals in CA3 area of the hippocampus, hilus of the dentate gyrus and in the vevrtal blade of the dentate gyrus, in 35-day-old animals only in the CA3 area of the...
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