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Neurobehavioral consequences of experimental psychosis in laboratory rats
Svojanovská, Markéta ; Stuchlík, Aleš (advisor) ; Telenský, Petr (referee)
Schizophrenia is a serious neuropsychiatric disease with a lifetime prevalence of 1% and it disrupts almost all mental functions. It manifests with many symptoms, which can be roughly classified into three main classes - positive, negative and cognitive dysfunctions. The psychosis, which can be often seen in schizophrenia, is a very serious problem that along with all other symptoms influences the patients' clinical status as well as quality of their life. As no direct causes or causal treatments for schizophrenia are known, scientist often focus on animal models of schizophrenia as tools for investigating mechanisms that can take a part in real disease and for seeking novel antipsychotics. This thesis aims at investigating two-week subchronic treatment with dizocilpine (MK-801), a non-competitive antagonist of NMDA receptors, in Wistar and Long-Evans rats aged 30 (PND 30) and 60 days (PND 60) at the onset of the treatment. Subsequently, long-term neurobehavioral consequences of this experimental psychosis were studied by testing rats at three behavioral tasks: the Elevated-plus maze (EPM), the Morris water maze (MWM) and active place avoidance on a rotating arena (Carousel). The Western blot method was used to determine post-mortem changes in expression of the NR1, NR2A and NR2B subunits of the...
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Flexibility in spatial cognition of rat
Staňková, Anna ; Svoboda, Jan (advisor) ; Telenský, Petr (referee)
5 Abstract Cognitive flexibility is an ability to adapt a behavior according to a dynamic changes in an environment. It belongs to executive functions, along with the processes of working memory, attention, motivation and others. Flexibility is important in the process of changing "stimulus-response" contingency at the time when the initial stimulus no longer leads to reward. According to the nature of the changes we can distinguish three types of cognitive flexibility: reversal learning, intradimensional set shifting and extradimensional set shifting. The processes of cognitive flexibility take place in fronto-striato-thalamic circuit with numerous connections to other brain regions, especially the limbic system. Deficit in cognitive flexibility belongs among cognitive symptoms of schizophrenia, a psychiatric illness we studied in the experimental part of this work using its analogue in rat. The aim of the experimental work was to test cognitive flexibility deficit in the rat model of schizophrenia-like behavior in the Carousel maze in four versions of task with different cognitive load. Animal model of schizophrenia was induced by acute administration of non-competitive NMDA receptor antagonist MK-801 at doses of 0.05 and 0.10 mg/kg i.p. Reversal learning was not damaged in this type of task following the...
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