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Neurogenesis in the adult brain, its regulation and possible functions
Pištíková, Adéla ; Stuchlík, Aleš (advisor) ; Jiruška, Přemysl (referee)
In this thesis I examine neurogenesis in the adult brain. Neurogenesis takes place in two main neurogenic areas. One area is located at the side of the forebrain ventricle and the other in dentate gyrus of the hippocampus. The forebrain ventricle neurogenesis is important for olfactory discrimination and olfactory memory. In the hippocampus, its function is unclear, but there are several hypotheses about its possible significance. We assume it might function in pattern separation and also be involvedin preventing interference between memory traces. The last chapter I dedicate to the positive and negative regulation of neurogenesis. The manipulations enhancing neurogenesis include voluntary physical activity, enriched environment and SSRI antidepressants. The negative impact on neurogenesis is exerted among other factors by stress, irradiation and a cytostatic Temodal, which is used methodologiclly to block neurogenesis.
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Using the Carousel Maze as a test of cognitive symptoms in an animal model of schizophrenia
Buchtová, Helena ; Landová, Eva (advisor) ; Jiruška, Přemysl (referee)
Spatial behaviour of animals is used to model cognitive human abilities such as declarative learning and memory. Cognitive deficits accompany a number of neuropsychiatric disorders and their treatment is most problematic. Schizophreniais one of these disorders. Behavioral, neurochamical, and molecular evidence point to a critical role of the NMDA glutamatergic receptors in the pathogenesis of schizophrenia. Disruption of their function results in behavioral and physiological changes including dysregulation of the depaminergic neurotransmission. This fact is used to model schizophrenia-related symptoms by systemic administration of NMDA receptor antagonists. Models combining administration of these drugs with behavioral tests aimed at specific cognitive deficits are of particular interest. This thesis use existing evidence to show that the Carousel Maze is such a behavioral test, which uses dynamic spatial learning to test the ability to coordinate discordant information and specific use of the relevant cues.
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Analysis of high-frequency activity in electroencephalogram of animal epilepsy model
Havel, T. ; Kudláček, J. ; Jiruška, Přemysl ; Ježdík, P. ; Čmejla, R.
High frequency oscillations (HFO) are believed to be a new specific biomarker of epileptogenic tissue. According to the reported findings, we hypothesized that HFOs occur more specific to the epileptogenic tissue. To test this hypothesis, we analyzed intracranial electroencephalograms (iEEG) of three subjects of animal epilepsy model. Overall 180 minutes of iEEG records were processed by the automatic high frequency activity detector and further analyzed. The dominant frequency of each segment was determined and categorized as ripples (80-200 Hz) or fast ripples (200-1000 Hz). Even though overall number of HFO detections predominate in the hemisphere where epileptic focus is located, in comparison of each brain structure separately our hypothesis cannot be fully confirmed.
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Case study of intracranial EEG records of patients with focal cortical dysplasia type I and II
Balach, J. ; Ježdík, P. ; Čmejla, R. ; Kršek, P. ; Jiruška, Přemysl
In this study we try to find out if it is possible to differentiate type of focal cortical dysplasia by features obtained from intracranial EEG. We compare occurrence and rates of three biomarkers present in epilepsy in patients with focal cortical dysplasia type I and II. Case study is made on long term night records of 6 pediatric patients. Detection of interictal epileptiform discharges and high-frequency oscillations is made by automated algorithms, delta brush are marked visually. Position of lesion and electrodes inside were obtained from MRI. In individual rates were not found difference on significant level. No major significance were found, but as promising seem to be ratio inside to outside rates of high-frequency oscillations and presence of delta brush, which were found only in patients with focal cortical dysplasia type II.
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Techniques of intracranial EEG processing in a model of temporal lobe epilepsy
Kudláček, Jan ; Jiruška, Přemysl
To understand the role of various limbic structures in pathophysiology of temporal role epilepsy requires understanding of its functional organization. We have developed technique of recording of spontaneous and evoked acitvity in chronic model of temporal lobe epilepsy. In addition, we created a computer programme which allows sequential processing of large data sets and analysis and quantification of spontaneous epileptic activity and evoked potentials. This programme implements various techniques of seizure, HFO and interictal discharge detection
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Identification of epileptogenic neocortical areas by analysis of spatial distribution of interictal discharges
Janča, R. ; Kršek, P. ; Ježdík, P. ; Čmejla, R. ; Tomášek, M. ; Elišák, M. ; Jefferys, J. G. R. ; Jahodová, A. ; Komárek, V. ; Marusič, P. ; Jiruška, Přemysl
Algorithm utilizing principal component analysis was developed to analyze spatial distribution of interictal epileptiform discharges. This technique enables to seaprate interictal discharges into functionally significant clusters. Cluster properties can be used to identify epileptogenic components of the irritative zone
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