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Role of ventral hippocampus and medial prefrontal cortex in behavioral flexibility in rodents
Černotová, Daniela ; Svoboda, Jan (advisor) ; Telenský, Petr (referee)
Behavioral adaptation to a continuously changing environment is critical for the survival of the animals, but also day-to-day interactions in the human world. The main components maintaining flexibility in cognition and behavior are well-established and depend mostly on proper intercommunication within the prefrontal cortex (PFC) and striatum. Some parts of the PFC are densely innervated by the ventral hippocampus (vHPC), which has a great impact on its functioning. Also, hippocampal-prefrontal circuit dysfunction has been shown to disrupt the integrity of flexible cognition in some neuropsychiatric diseases. Therefore, the exact functional role of this pathway is an indispensable part of the research. The aim of this study was to test the role of the vHPC and the medial PFC (mPFC) in an active place avoidance task on a rotating arena in 1) two flexibility task variants - reversal learning and set- shifting - and 2) the spatial memory retrieval. We inactivated these structures by muscimol (GABAA receptor agonist) in a variety of unilateral, bilateral, and combined local injections. Disrupted performance was apparent in reversal learning in vHPC-inactivated rats. No effect was seen in mPFC-inactivated rats. Impairments after the task acquisition were observed in bilateral vHPC and mPFC inactivations...
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Neuropharmacology of spatial navigation, cognitive coordination and flexibility tests in animal models
Prokopová, Iva ; Stuchlík, Aleš (advisor) ; Vyklický, Ladislav (referee) ; Blahoš, Jaroslav (referee)
Spatial navigation, cognitive coordination and behavioral flexibility belong amongst cognitive functions, which play a role in many neuropsychiatric disorders. Behavioral tasks have proved to be useful paradigms to test these functions in pharmacological or genetic animal models. First aim was to determine a potential interaction between β-adrenergic and α1-adrenergic or D2-dopaminergic systems. Spatial navigation and coordination were impaired in both studies during co-aplication of subthreshold doses of drugs. Used substances belong to group of widely prescribed drugs, thus our results could be implicated in clinical practice. Another study examined an acute effect of MK-801 (animal model of schizophrenia) on behavioral flexibility in Carousel maze and the Morris water maze (MWM). Carousel maze showed higher sensitivity with impairments from 0.08 mg.kg-1 compared to 0.10 mg.kg- 1 in MWM. The final experiment aimed at testing the effect of reduced expression of Nogo-A protein on spatial navigation and behavioral flexibility of rats. A battery of tests in the Carousel maze revealed impairment in cognitive functions, MWM showed unaffected working memory of rats. Our results support the hypothesis linking Nogo-A knock-down rats with neuropsychiatric symptoms and cognitive disorders. Key words:...
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Role of ventral hippocampus and medial prefrontal cortex in behavioral flexibility in rodents
Černotová, Daniela ; Svoboda, Jan (advisor) ; Telenský, Petr (referee)
Behavioral adaptation to a continuously changing environment is critical for the survival of the animals, but also day-to-day interactions in the human world. The main components maintaining flexibility in cognition and behavior are well-established and depend mostly on proper intercommunication within the prefrontal cortex (PFC) and striatum. Some parts of the PFC are densely innervated by the ventral hippocampus (vHPC), which has a great impact on its functioning. Also, hippocampal-prefrontal circuit dysfunction has been shown to disrupt the integrity of flexible cognition in some neuropsychiatric diseases. Therefore, the exact functional role of this pathway is an indispensable part of the research. The aim of this study was to test the role of the vHPC and the medial PFC (mPFC) in an active place avoidance task on a rotating arena in 1) two flexibility task variants - reversal learning and set- shifting - and 2) the spatial memory retrieval. We inactivated these structures by muscimol (GABAA receptor agonist) in a variety of unilateral, bilateral, and combined local injections. Disrupted performance was apparent in reversal learning in vHPC-inactivated rats. No effect was seen in mPFC-inactivated rats. Impairments after the task acquisition were observed in bilateral vHPC and mPFC inactivations...
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Neuropharmacology of spatial navigation, cognitive coordination and flexibility tests in animal models
Prokopová, Iva ; Stuchlík, Aleš (advisor) ; Vyklický, Ladislav (referee) ; Blahoš, Jaroslav (referee)
Spatial navigation, cognitive coordination and behavioral flexibility belong amongst cognitive functions, which play a role in many neuropsychiatric disorders. Behavioral tasks have proved to be useful paradigms to test these functions in pharmacological or genetic animal models. First aim was to determine a potential interaction between β-adrenergic and α1-adrenergic or D2-dopaminergic systems. Spatial navigation and coordination were impaired in both studies during co-aplication of subthreshold doses of drugs. Used substances belong to group of widely prescribed drugs, thus our results could be implicated in clinical practice. Another study examined an acute effect of MK-801 (animal model of schizophrenia) on behavioral flexibility in Carousel maze and the Morris water maze (MWM). Carousel maze showed higher sensitivity with impairments from 0.08 mg.kg-1 compared to 0.10 mg.kg- 1 in MWM. The final experiment aimed at testing the effect of reduced expression of Nogo-A protein on spatial navigation and behavioral flexibility of rats. A battery of tests in the Carousel maze revealed impairment in cognitive functions, MWM showed unaffected working memory of rats. Our results support the hypothesis linking Nogo-A knock-down rats with neuropsychiatric symptoms and cognitive disorders. Key words:...
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