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Gene expression pattern in the adult brain of the experimental rat after prenatal exposure to methamphetamine
Tomášková, Anežka ; Černá, Marie (advisor) ; Rudá, Jana (referee)
Introduction: Methamphetamine is a drug frequently taken by drug-addicted pregnant women and happens to be one of the most commonly used drugs in the Czech Republic. This drug passes easily through a placental barrier into the fetus. Thus it can negatively affect not only the mother but also the prenatal development of her offspring. Objectives: This research aims to provide a general screening of gene expression in selected regions of the F1 generation of the brain prenatally affected by methamphetamine, to verify whether exposure to methamphetamine affects the generation of offspring of exposed females at the level of gene expression in selected regions of the brain, and to valuate possible changes in gene expression. Methods: In selected parts of the brain, collected from a rat, the microarray hybridization and the real-time PCR were set to evaluate express changes in the expression of selected genes. Results: Statistical analysis of the microarray hybridization did not show a significantly altered gene expression in the tested genes. Only boundary values for 13 genes were measured, which were further tested by the real-time PCR. After a statistic evaluation of the real-time PCR, the significantly altered expression was found in 2 genes. The notably changed expression of DRD3 and TACR3 genes...
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Otimization of a dose of temozolomide for efficient reduction of adult neurogenesis in the laboratory rat
Pištíková, Adéla ; Stuchlík, Aleš (advisor) ; Jiruška, Přemysl (referee)
The goal of this study is to find an optimal dose of cytostatic Temozolomide (TMZ) for Long-Evans strain of rats. This dose should reduce neurogeneis while having a minimal pernicious health side-effects. Temozolomide is newly used to suppress neurogenesis but similarly to any other cytostatic has an effect on all dividing cells in an organism. This can affect health of an animal. Contrary to the mice, there was no systematic attempt to establish optimal dose. In our experiment rats were divided into four groups - one control group and three treatment groups which received different doses of temozolomide (10, 25, 40 mg/kg of TMZ). To detect level of neurogenesis cells were labeled by bromodeoxyuridine. During the experiment blood element counts were assessed, sensorimotoric tests were conducted, and weight increment was monitored. The results indicate that dose of 10mg/kg is adequate as it reduces neurogenesis by 64% compared to the control group and does not significantly differ from higher doses. In this group weight increment is comparable with the control group, while in the higher doses of TMZ weight increment is significantly lower. Effect of myelosupression is same for all treatment groups.
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Functional differentiation in the hippocampus
Vondráková, Kateřina ; Telenský, Petr (advisor) ; Stuchlík, Aleš (referee)
This work has been focused on anatomical and functional differentiation of the hippocampus. Hippocampus, as one of the most studied structures in the brain has an irreplaceable role in encoding, consolidation and recall of memories. In the early 20th century, Ramon y Cajal has divided hippocampus into 3 subregions, Ammon's horn (CA1-CA3 region), dentate gyrus and subiculum. Diferences in gene expresion, principal cell features and organization of connections with other structures suggests further division of the hippocampus according to septo-temporal axis, into ventral, dorsal and intermedial zone. Most importantly, the efects of impairment or inactivation of the individual subregions of the hippocampus, allow us to determine their prospective functions.
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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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Hippocampal coding of positions of inaccessible objects
Hrůzová, Karolína ; Stuchlík, Aleš (advisor) ; Kudláček, Jan (referee)
The survival of the animals depends on their ability to memorize locations and to use behavioral spatial navigation strategies. The crucial structure for this type of behavior and memory is the hippocampus, by its ability to create a cognitive map. In this structure, there are specialized pyramidal cell called place cells. They respond by their complex firing pattern to specific animal's location in the environment. Even though many studies have investigated the role of hippocampal pyramidal cells in spatial navigation and object position discrimination, their function during inaccessible object position discrimination is not yet clarified. In our experiment, rats were trained in a behavioral task to discriminate between rewarded and nor- rewarded positions of object located in an inaccessible space. We investigated the role of individual hippocampal cells during this task by single neuron electrophysiology. The first aim of this study was to decide which of two configurations of objects presented on a computer screen during spatial object discrimination task rats can discriminate easily. The second aim is to show whether and how information about the position of inaccessible objects is represented in the hippocampus using single-neuron electrophysiology. We found out, that animals did not reach...
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The Processing of Social Information by Neurons in the Rat's Hippocampus.
Hanzlík, Adam-František ; Kelemen, Eduard (advisor) ; Ježek, Karel (referee)
ABTRACT In order to survive, an animal must be able to integrate vital information about it's surroundings, such as information about the environment and the social interactions therein. Decades of research have established the hippocampal formation as a structure indispensable for spatial memory. It was only recently, though, that evidence has emerged suggesting that the hippocampus, most notably the dorsal CA2 region, also supports the encoding of social information. New behavioural as well as electrophysiological evidence appeared, highlighting the importance of sleep for the processing of social information. In my thesis, I used microelectrodes to record the electrophysiological activity of individual CA2 neurons from freely-moving rats, during wake as well as in sleep. In order to study the processing of social information by hippocampal neurons, I employed a novel experimental paradigm in which social stimulation, in the form of two rat conspecifics, was presented in a spatial context. I report that the discharge of some CA2 neurons was organised within the experimental maze, even after social stimulation was added. Moreover, I observed that the spatial activity of neurons changed after the addition of social stimuli, and that it further changed when the location of the two conspecifics was shuffled....
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Hippocampal neuronal representation of a moving object in a novel spatial avoidance task
Ahuja, Nikhil ; Stuchlík, Aleš (advisor) ; Jiruška, Přemysl (referee) ; Telenský, Petr (referee)
In real world environments, animals need to organize their behavior relative to other moving animals or objects; when hunting a predator, when migrating in groups or during various social interactions. In all of these situations, the animal needs to orient relative to another moving animal/object. To understand the role of the hippocampus in this ability we adopted a two-step approach. We developed a task that would mimic important elements of this behavior in the laboratory. The task required the rats to assess not only their distance from the moving object but also their position relative to the object. We further studied how neurons in the hippocampal CA1 subfield encode the subject, the moving object and the environment in the behavioral paradigm and how do these representations interact among themselves. In rats, we aimed to characterize spatial behaviors relative to moving objects and to explore the cognitive mechanisms controlling these behaviors. Three groups of animals were trained to avoid a mild foot-shock delivered in one of three positions: either in front, on the left side, or the right side of a moving robot. Using different variations of the task, we also probed whether avoidance was simply due to increased noise level or size of the retinal image or appearance of the robot. As the...
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The effect of sleep on consolidation of episodic-like memory in rats
Petránová, Erika ; Kelemen, Eduard (advisor) ; Svoboda, Jan (referee)
We can notice the positive effects of sleep on many functions of our organism. For a long time we have observed the interconnection between sleep and memory and today we already know, that different sleep phases correlate with an improvement of different memory types. One of the hypotheses, that explain the positive effect of sleep on strengthening of the memory representations, is its irreplaceable active role in the process of memory consolidation. The memory consolidation of episodic type in animals, which processes memories into events with time and space context, could according to this theory occur due to two phase sleep process, in which each phase has a specific role. The theoretical part of this thesis will familiarize the reader with the problematic of organization of time and space in our brain, and introduce him to the foundations of electroencephalography (EEG) and offer a detailed introduction into the discussed hypothesis of active sleep consolidation. The practical part is then focused on the confirmation of the already mentioned hypothesis through the combination of comparison of results from the behavioral task of 2 groups of animals with different sleep manipulation and of the analysis of EEG signal recorded during the experiment before and after the training. The behavioral task...
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Hippocampal coding of positions of inaccessible objects
Hrůzová, Karolína ; Stuchlík, Aleš (advisor) ; Kudláček, Jan (referee)
The survival of the animals depends on their ability to memorize locations and to use behavioral spatial navigation strategies. The crucial structure for this type of behavior and memory is the hippocampus, by its ability to create a cognitive map. In this structure, there are specialized pyramidal cell called place cells. They respond by their complex firing pattern to specific animal's location in the environment. Even though many studies have investigated the role of hippocampal pyramidal cells in spatial navigation and object position discrimination, their function during inaccessible object position discrimination is not yet clarified. In our experiment, rats were trained in a behavioral task to discriminate between rewarded and nor- rewarded positions of object located in an inaccessible space. We investigated the role of individual hippocampal cells during this task by single neuron electrophysiology. The first aim of this study was to decide which of two configurations of objects presented on a computer screen during spatial object discrimination task rats can discriminate easily. The second aim is to show whether and how information about the position of inaccessible objects is represented in the hippocampus using single-neuron electrophysiology. We found out, that animals did not reach...
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