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Functions of the adult neurogenesis
Šejnová, Gabriela ; Stuchlík, Aleš (advisor) ; Melkes, Barbora (referee)
Neurogenesis in adult mammals was first discovered in the second half of the 20th century and its mechanisms, regulation and possible functions have been researched eversince. Scientists have so far been able to describe the process of neuronal development as well as some possible influences. However, the role of this phenomenon is still being discussed. This thesis is focused on neurogenesis in the dentate gyrus in hippocampus, a pair structure located in the central part of the temporal lobe. The main aim is to describe the recent findings and research models as well as the assumed functions. The most recent theories find the role of hippocampal neurogenesis in pattern separation, memory resolution, contextual memory or memory consolidation. These hypotheses are quite variable due to the broad range of research methods and their interpretations, however, none of them seems to disprove the others. Key words: neurogenesis, functions, behavior, hippocampus, learning
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The influence of stochastic behaviour of ion channels on the signal and information transfer at excitable neuronal membranes
Šejnová, Gabriela ; Kuriščák, Eduard (advisor) ; Maršálek, Petr (referee)
The stochastic behavior of voltage-gated ion channels causes fluctuations of conductances and voltages across neuronal membranes, contributing to the neuronal noise which is ubiquitous in the nervous system. While this phenomenon can be observed also on other parts of the neuron, here we concentrated on the axon and the way the channel noise influences axonal input-output characteristics. This was analysed by working with our newly created computational compartmental model, programmed in Matlab environment, built up using the Hodgkin-Huxley mathematical formalism and channel noise implemented via extended Markov Chain Monte Carlo method. The model was thoroughly verified to simulate plausibly a mammalian axon of CA3 neuron. Based on our simulations, we confirmed quantitatively the findings that the channel noise is the most prominent on membranes with smaller number of Na+ and K+ channels and that it majorly increases the variability of travel times of action potentials (APs) along axons, decreasing thereby the temporal precision of APs. The simulations analysing the effect of axonal demyelination and axonal diameter correlated well with other finding referred in Literature. We further focused on spike pattern and how is its propagation influenced by inter-spike intervals (ISI). We found, that APs fired...
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Functions of the adult neurogenesis
Šejnová, Gabriela ; Stuchlík, Aleš (advisor) ; Melkes, Barbora (referee)
Neurogenesis in adult mammals was first discovered in the second half of the 20th century and its mechanisms, regulation and possible functions have been researched eversince. Scientists have so far been able to describe the process of neuronal development as well as some possible influences. However, the role of this phenomenon is still being discussed. This thesis is focused on neurogenesis in the dentate gyrus in hippocampus, a pair structure located in the central part of the temporal lobe. The main aim is to describe the recent findings and research models as well as the assumed functions. The most recent theories find the role of hippocampal neurogenesis in pattern separation, memory resolution, contextual memory or memory consolidation. These hypotheses are quite variable due to the broad range of research methods and their interpretations, however, none of them seems to disprove the others. Key words: neurogenesis, functions, behavior, hippocampus, learning
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