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Neurons expressing calcium-binding proteins in neocortex of patients with epilepsy and in the perirhinal cortex of the rat
Barinka, Filip ; Druga, Rastislav (advisor) ; Mareš, Jan (referee) ; Paleček, Jiří (referee)
Cortical inhibitory interneurons play an important role in cortical neuronal circuits in physiological state and probably also in the etiopathogenesis of epilepsy. The first part of my research work was focused on calretinin expressing (CR+) interneurons in a) non-malformed temporal neocortex in patients with refractory temporal lobe epilepsy associated with hippocampal sclerosis (nHSTN), b) in focal cortical dysplasias (FCD). FCD represent a prominent cause of pharmacologically intractable epilepsy. Main goal of our study was to show whether CR+ interneurons exhibit any change in human nHSTN and in various types of FCD and to compare it with previously well documented decrease of parvalbumin expressing (PV+) interneurons. We used immunohistochemical staining for CR. Brain tissue from 24 patients surgically treated for pharmacoresistant epilepsy as well as post-mortem acquired control neocortical samples of 9 patients were examined. CR+ interneuronal density in all types of samples was evaluated. In nHSTN, no change compared to controls was found in CR+ neuronal density. The density of CR+ interneurons was significantly decreased in FCD type I (to approximately 70 % of control values) and even more in FCD type II (to approximately 50 % of control values). The decrease of CR+ interneuronal density was shown...
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Functional consequences of epileptic seizures and CNS hypoxia-ischemia
Krýsl, David ; Mareš, Jan (advisor) ; Druga, Rastislav (referee) ; Jiruška, Přemysl (referee)
Hypoxic - ischemic CNS lesions and epileptic seizures share many common pathophysiologic features. Basic mechanisms , either detrimental ( excitotoxicity , free radicals, inflammation , changes in permeability of the blood brain barrier , particularly necrotic and apoptotic cell death) , or reparative ( gliosis , neuroplasticity , neurogenesis , vascular proliferation ) occur in Both types of damage , but may be expressed in varying degrees, and may take place in different time term. Hypoxia , but also global and focal ischemia, CNS are in humans and in experimental models under certain conditions accompanied by epileptic seizures. Epileptic seizures vice versa acutely and chronically affect cerebral blood flow (CBF ) . CBF and cerebral metabolism is significantly affected during status epilepticus ( SE). CBF changes can significantly contribute to pathophysiological consequences of seizures and may have links with some of their clinical manifestations (eg Todd's postparoxysmální hemiparesis ( MS Mathews et al. , 2008; Yarnell PR 1975) ) . Focal ischemia, CNS has often consequences in distant , but functionally linked areas ( diaschisis ) . There is a remote influence not only the blood flow and metabolism , but also excitability (Andrews, RJ , 1991 Buchkremer - Ratzmann I. et al. 1996b ) . Also in the...
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Neuromorphology of the visual system in microphthalmic mammals: Identification of the primary visual cortex in strictly subterranean African mole-rats and visual acuity in echolocating bats
Miklušová, Zuzana ; Němec, Pavel (advisor) ; Druga, Rastislav (referee)
Microphthalmia has evolved in evolution many times independently within unrelated groups of mammals (e.g., subterranean rodents, insectivores, afrosoricids and marsupials; echolocating bats, and shrews). Due to such extensive convergent evolution, investigation of mammals with reduced eyes provides a unique approach for understanding the adaptive significance of sensory regression and the impact of peripheral reduction on organization of central sensory structures. This thesis focuses on two issues. In the first part of this thesis, a search for the primary visual cortex (V1) has been conducted in two bathyergid species, the Ansell's mole-rat, Fukomys anselli and the giant mole-rat Fukomys mechowii. Utilizing retrograde tracing and the technique of flattening and sectioning the cortex to visualize area boundaries, I have evidenced the presence of the V1 in the both species. It was small and, in comparison to other rodents, displaced laterally. Multiple injections of different tracers in different regions of the V1 resulted in retrograde labeling of distinct region of the dorsal lateral geniculate nucleus (DLG), implying conservation of the retinotopic organization within the geniculo-striate pathway. However, any injection into V1 resulted also in a robust retrograde labeling of the multimodal...
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Primary sensory cortices of microphthalmic mammals, adaptations to habitat and lifestyle
Miklušová, Zuzana ; Němec, Pavel (advisor) ; Druga, Rastislav (referee)
Microphthalmia has evolved in evolution many times independently within unrelated groups of mammals (e.g., rodens, echolocating bats, shrews). Due to such extensive convergent evolution, investigation of mammals with reduced eyes provides a unique approach for understanding the adaptive significance of sensory regression, the impact of peripheral reduction on organization of central sensory structures and cross-modal reorganization or compensation. In this thesis I review our current knowledge concerning the organization of the primary sensory cortex in microphthalmic mammals. In subterranean species (the eastern mole, Scalopus aquaticus; the star-nosed mole, Condylura cristata; the blind mole rat, Spalax ehrenbergi; the naked mole rat, Heterocephalus glaber) is obvious expansion of somatosensoty cortex, which processes tactile information.The sense of touch plays a pivotal role in orientation in their dynamically changing three-dimensional burrow systems. Microphthalmic, echolocating bats whose body is adapted to flight have topographicly reorganized somatosensory cortex, reduced the visual cortex and expanded, complexly organized acoustic cortex. Terrestrial shrews (Soricidae, Insectivora) do not posses any specific adaptations at level of the sensory cortex. Interestingly, their primary visual cortex is...
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Hemoprotein Nitric Oxide Synthase in Aplysia Californica
Buganová, Michaela ; Martásek, Pavel (advisor) ; Pelouch, Václav (referee) ; Druga, Rastislav (referee)
Nitric oxide (NO) plays a crucial role in neuronal signaling in a variety of eukaryotic and prokaryotic organisms. Nitric oxide synthases (NOS) are heme-containing monooxygenases that catalyze the oxygen dependent oxidation of L-arginine to NO and L-citrulline. The NO produced by NOS activity is a gaseous molecule that diffuses easily through membranes and acts inter or intracellularly. NO activates metal-containing enzymes, including soluble guanylate-cyclase (sGC) that increase levels of the messenger molecule cyclic 3,5-guanosine monophosphate (cGMP) (1, 2) which in turn mediate various pathophysiological or physiological functions in neurons. Nevertheless, many aspects of nitrergic neurons and NO function in the central nervous system (CNS) are unclear. The aim of research described in this thesis was to characterize neuronal NOS, proteins metabolically linked to NOS and NO signaling pathways in the CNS of Aplysia cali/ornica (Aplysia), a popular experimental model in cellular and system neuroscience. The biochemical characteristics of Aplysia NOS (AcNOSj described here revealed its calcium-/calmodulin-(Ca/CaM) and NADPH dependence. A representative set of inhibitors for mammalian NOS isoforms also suppressed NOS activity in Aplysia Polyclonal anti-rat nNOS antibodies hybridized with a putative purified...
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