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Separation of hippocampal function in Morris water maze and in active place avoidance by alternance protocol
Vojtěchová, Iveta ; Petrásek, Tomáš (advisor) ; Hiadlovská, Zuzana (referee)
In this work, we examined the executive functions of the hippocampus at the behavioral level as a so-called behavioral separation in adult rats. We studied an impact of day-to-day alternation versus sequential learning (and the order of learning) of two spatial tasks (Morris Water Maze and Active Allothetic Place Avoidance) testing different hippocampal functions (experiment 1), or an impact of sequential versus alternating learning of one task (Active Allothetic Place Avoidance) in two different rooms (experiment 2), on performance. We found out that rats are able to learn both tasks as well as to discriminate between the two contexts regardless of the order or alternating of learning. Because such executive functions are impaired in human patients suffering from schizophrenia, we used this procedure also in the rat model of schizophrenia induced by acute intraperitoneal application of dizocilpine (MK-801), glutamate NMDA receptors antagonist, in the dose of 0.08 mg/kg. We failed to selectively disrupt the behavioral separation, however, we observed general learning deficit and hyperlocomotion regardless of the alternation in the Active Allothetic Place Avoidance task in these rats. The cognitive impairments in connection with learning after such low dose of MK-801 in this task have not yet been...
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Memory and cognitive coordination impairment in rat models of neuropsychiatric diseases
Vojtěchová, Iveta ; Stuchlík, Aleš (advisor) ; Syka, Josef (referee) ; Hort, Jakub (referee)
The memory and spatial navigation are extremely important brain functions for humans, but they are often the question of life and death for animals. In humans, memory can be disrupted by various neuropsychiatric disorders. The patients suffering from Alzheimer's dementia (AD) have impaired working and long-term memory, spatial navigation, higher cognitive functions and social memory. The deficit of cognitive coordination (the skill to recognize the relevancy of incoming information) and disorientation belong to the symptomatology of schizophrenia. Intelectual disability appears in some patients with autism spectrum disorder. Unfortunately, it is not possible to cure these disorders efficiently because the etiology is not known in the majority of patients. The causes leading to development of these disorders could be revealed using animal models. This thesis contributes to the characterization of the cognitive skills disruptions - as well as other behavioral alterations - in selected rat models of AD (transgenic McGill rat, non-transgenic Samaritan rat) and schizophrenia (lipopolysaccharide model of early postnatal, or prenatal, bacterial infection). The thesis also discusses the validity and limitations of these models. Our results showed a severe deficit of spatial navigation, learning and...
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Comparison of transgenic and streptozotocin models of Alzheimer in rats: validation of IntelliCage system for behavioral phenotypization
Svobodová, Eva ; Telenský, Petr (advisor) ; Svoboda, Jan (referee)
Animal models of Alzheimer's disease display cognitive insufficiencies which mimic human symptoms and occur at a given age or post-treatment time. Animals are typically tested using canonical behavioral tests, lasting minutes and taking place mostly in the non-active period of the daily cycle. Animals are exposed to certain amounts of manipulation-induced stress. Our work represents a validation study for the rat behavioral system IntelliCage. The tested individuals live freely in a group and their behavior is monitored continuously. It is however possible to set up individual tests for each animal or a group of animals. The rats are not subject to human manipulation and hence the results are not affected by manipulation-induced stress. We tested early cognitive impairment in the transgenic rat model TgF344-AD at 6 - 8 months of age. Further, we tested two most common protocols of the streptozotocin model, i.e. single dose of intracerebroventricular 3 mg/kg streptozotocin and double dose 48 hrs apart. Results were compared with the canonical Morris Water Maze (MWM) test. In the MWM test, transgenic animals did not differ from controls in any of the studied parameters. The streptozotocin model displayed a deficit only in the double dose group. However in the IntelliCage, transgenic animals displayed...
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Mnemonic and behavioural effects of biperiden, an M1-selective antagonist, in the rat
Popelíková, Anna ; Stuchlík, Aleš (advisor) ; Telenský, Petr (referee)
Due to the persisting lack of reliable animal models of cognitive impairment with good translational validity, researches strive to discover new ways and tools to replicate symptoms of human neurodegenerative diseases in rodents. Recently, biperiden, an M1- selective muscarinic antagonist, has been proposed as a potential tool for generating fast screening models of mnemonic deficits such as seen in patients with Alzheimer's disease. Being highly selective for the M1 receptor, a predominant type of muscarinic acetylcholine receptors in the brain involved in cognitive processes, it has been speculated to possibly only influence cognition without causing sensorimotor side effects. Studies assessing the usability of this drug reported conflicting results. We have decided to expand the experimental data and evaluate biperiden's validity in several variants of the Morris water maze. The results of this study showed no significant effect of biperiden on cognitive flexibility, tested by reversal learning. In delayed-matching-to-position paradigm, which tests assesses working memory, we found a difference in performance between the two experimental groups; however, it cannot be unequivocally attributed to a memory impairment. No effects were observed in visible platform task, confirming a lack of...
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Separation of hippocampal function in Morris water maze and in active place avoidance by alternance protocol
Vojtěchová, Iveta ; Petrásek, Tomáš (advisor) ; Hiadlovská, Zuzana (referee)
In this work, we examined the executive functions of the hippocampus at the behavioral level as a so-called behavioral separation in adult rats. We studied an impact of day-to-day alternation versus sequential learning (and the order of learning) of two spatial tasks (Morris Water Maze and Active Allothetic Place Avoidance) testing different hippocampal functions (experiment 1), or an impact of sequential versus alternating learning of one task (Active Allothetic Place Avoidance) in two different rooms (experiment 2), on performance. We found out that rats are able to learn both tasks as well as to discriminate between the two contexts regardless of the order or alternating of learning. Because such executive functions are impaired in human patients suffering from schizophrenia, we used this procedure also in the rat model of schizophrenia induced by acute intraperitoneal application of dizocilpine (MK-801), glutamate NMDA receptors antagonist, in the dose of 0.08 mg/kg. We failed to selectively disrupt the behavioral separation, however, we observed general learning deficit and hyperlocomotion regardless of the alternation in the Active Allothetic Place Avoidance task in these rats. The cognitive impairments in connection with learning after such low dose of MK-801 in this task have not yet been...
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Testing of spatial orientation in leopard gecko ( Eublepharis macularius)
Voňavková, Monika ; Landová, Eva (advisor) ; Svoboda, Jan (referee)
The ability of the spatial orientation of the reptiles is not fully researched yet. It is unknown if reptiles use only simple types of navigation, for example cue learning (one key mark), or more difficult types, for example allothetic navigation (combination of marks) or cognitive map (mental representation of the area). The main aim of this thesis was examine the possibility of the spatial orientation in lizard leopard gecko (Eublepharis macularius) in modificated Morris water maze (MWM). Design of the experiments was based on Parallel Map Theory, a theory which describes using spatial information from more navigation frames. The leopard gecko preferences of orientation frames were tested . That means the ability to combinate the spatial information from the bearing maps (one mark and gradient) and the sketch maps (local marks). This ability is prerequisite for creating the integrated map. The research was also focused on the significance of the simple cue learning strategy and cognitive more difficult allothetic navigation for the orientation of leopard gecko. Leopard geckos can use the combination of information from the navigation frames, which indicate the possibility of integrated map creation. Usage of navigation strategies is individual. Keywords: reptiles, leopard gecko, spatial...
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