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Effects of Neurotransmission-Modulating Multipotent Compounds in Pharmacological Animal Models of Cognitive Deficit
Chvojková, Markéta ; Valeš, Karel (advisor) ; Kuchař, Martin (referee) ; Rudá, Jana (referee)
In preclinical research on Alzheimer's disease pharmacotherapy, attention is paid to multipotent compounds, enabling intensification of the effect by targeting multiple pathophysiological mechanisms. The aim of the thesis was to assess the effect of multipotent compounds and combination therapy in models of cognitive deficit in the rat. The mechanism of action of the tested compounds was modulation of neurotransmitter systems. The aim of the first part of the study was to compare the effect of experimental monotherapy and combination therapy with an N-methyl-D-aspartate (NMDA) receptor antagonist and a γ-aminobutyric acid type A (GABAA) receptor positive modulator in the trimethyltin-induced model. Superiority of the combination therapy was proven by histological analysis of hippocampal neurodegeneration; however, it did not reach statistical significance in the cognitive test. The other part of the thesis focused on multipotent tacrine derivatives. We demonstrated a positive effect of 6- chlorotacrine-6-nitrobenzothiazole hybrid, as well as 6-chlorotacrine-L-tryptophan hybrid, acting as acetylcholinesterase inhibitors, in the scopolamine-induced model of cognitive deficit. Besides, we demonstrated a low risk of serious side effects of other tacrine derivatives acting as NMDA receptor antagonists....
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The importance of NMDA antagonists in animal models of ischemic injury and major depressive disease
Kletečková, Lenka ; Valeš, Karel (advisor) ; Zach, Petr (referee) ; Ježek, Karel (referee)
Glutamatergic system is the main excitatory system and glutamatergic receptors are the most abundantly expressed in whole central nervous system. The most widespread type of glutamatergic receptors are N-methyl-D-aspartate (NMDA) receptors which are essential for physiological development of nervous tissue, synaptic plasticity and cognitive processes. On the other hand, over-activation of these receptors leads to excitotoxic damage of nervous tissue and serious neurological consequences for future quality of life. Disruption of glutamatergic system is common feature for hypoxic-ischemic damage, traumatic brain injury, neurodegenerative and neuropsychiatric diseases. Therefore glutamatergic system and specifically NMDA receptors are an attractive target for neuropharmacological research. Presented thesis explores the effect of several molecules with modulating inhibiting effect on NMDA receptor. Work is preferentially focused on application research; the main aim is evaluated therapeutic potential of studied compounds. First group of compounds is represented by neuroactive steroids pregnanolone glutamate and pregnanolone hemipimelate, which are allosteric inhibitors of NMDA receptor. Here, their neuroprotective effect is demonstrated in hypoxic-ischemic and excitotoxic damage of nervous tissue....
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Influence of intestinal microbiota on development of neurodegenerative diseases
Hakenová, Kristina ; Valeš, Karel (advisor) ; Vodička, Martin (referee)
Aging is associated with natural biological changes, which result in a decrease in the functional capacity of the body, which is also accompanied by an increased incidence of inflammatory processes that contribute to the development of neurodegeneration. The intestinal microbiota and its interaction with the intestine and the central nervous system play a key role in maintaining the function of biological homeostatic systems at an older age. This opens the possibility of influencing or modifying human microbiota for the development of therapeutic strategies. Based on the analysis of stool samples by HPLC MS / MS, the study confirmed the effect of selected probiotics on the modification of metabolic pathways and the proper functioning of the microbiota per se. The greatest effects were observed on tyrosine metabolism, tryptophan metabolism, arachidonic acid metabolism and bile acid biosynthesis metabolism. A positive effect of selected probiotic bacteria was found in the memory component of cognitive functions. Significant improvements were observed in verbal learning and verbal memory. In subjects with mild cognitive impairment, the progression of cognitive deficit has been slowed. Significant improvement was also observed for executive functions. These findings were not followed by a subjective...
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Optical Signals of Brain
Konopková, Renata ; Otáhal, Jakub (advisor) ; Kittnar, Otomar (referee) ; Valeš, Karel (referee)
Intrinsic optical signals are the signals reflecting changes in transmittance or reflectance of the light illumitating the tissue. Registration of such changes can be applied for the detection of physiological condition in the slices of biological tissues (in vitro) or in the whole animal (in vivo). The aim of this project is to introduce this topic and show different possibilities for the detection of changing optical properties of nervous tissue both in vitro and in vivo. The detection system of both light source and attachment of the optical fibre to the skull of the animal for in vivo experimets have been designed. The proper experimental part of the study have been done in hippocampal tissue slices and shows the correlation of the tissue activity and the optical signal at level of ion channels, glutamatergic synaptic activity, glial component of the signal and mitochondrial signal. We are dealing with the source of the noice that we record while detecting rather subtle changes of optical properties. We are indroducing the software VisionBrain for synchronous detection of both electrical and optical changes. Keywords: Intrinsic optical signals, hippocampus, imaging, biomechanics
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Does prenatal methamphetamine exposure induce cross-sensitisation to drugs in adult male and female rats?
Macúchová, Eva ; Šlamberová, Romana (advisor) ; Šulcová, Alexandra (referee) ; Valeš, Karel (referee)
Women, who abuse drugs during pregnancy, expose not just themselves but also their developing foetus to impairing effects, which can have potentially harmful and even long- term effects on the exposed children. For some years, methamphetamine (MA) has dominated the illicit drug market in the Czech Republic and Slovakia; additionally this drug is on the rise worldwide. It is one of the most accessible drugs, and in many cases the first choice drug for many drug-addicted pregnant women; in part due to its anorectic and stimulant effects. These women are rarely aware of the consequences of their behaviour and their pregnancy is hardly ever a good enough reason for giving up drug use. These findings are supported by many experimental studies that show the damaging effects of maternal MA exposure on their offspring. There is growing evidence that exposure to MA in utero not only causes birth defects and delays in infant development, but also impairs the brain reward neural pathways of a developing offspring in such a way, that it could increase the predisposition for drug addiction later in life. Previously published animal studies have shown that offspring of mothers exposed to MA during pregnancy are more sensitive to MA when they encounter this drug later in adulthood. With respect to increased...
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Determination of critical developmental periods for effects of methamphetamine on rat behavior in adulthood
Hrebíčková, Ivana ; Šlamberová, Romana (advisor) ; Cendelín, Jan (referee) ; Valeš, Karel (referee)
Aim: The aim of the Ph.D. thesis was to find out which of the neuro-ontogenetic stages of laboratory rat is more significant for the methamphetamine (MA) exposure on the behavior in adulthood and to determine a critical developmental period for the effects of this drug. In the experimental part of the study was to test the influence of prenatal and neonatal MA exposure on behavior, social interaction, cognition and drug-seeking behavior in adulthood. Methods: Adult female rats were exposed to MA (5 mg/ml/kg) or saline (S) (1 mg/kg) during different stages of gestation and lactation. The tested substances were administered subcutaneously during the first half of gestation (ED 1-11), the second half of gestation (ED 12-22) or during early lactation (PD 1-11). The effect of prenatal MA exposure was transmitted to pups via placental barrier; the effect of MA exposure during early lactation was transmitted via the breast milk. In order to compare the rate of drug transmission by indirect MA exposure via the breast milk, we chose another group of offspring that we administered the tested substances directly subcutaneously during the same application period (PD 1-11). In this way we obtained 8 groups of exposed pups: ED 1-11 MA, S; ED 12-22 MA, S; PD 1-11 indirectly MA, S; PD 1-11 directly MA, S. These...
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Human in vitro models for epilepsy research
Hebenstreitová, Kristýna ; Danačíková, Šárka (advisor) ; Valeš, Karel (referee)
Epilepsy is the most common chronic neurological disease that affects around 1 % of the world population. It is a multifactorial disease, which is characterised by recurrent seizures. Present pharmacological treatment is symptomatic and approximately one third of the patients develop pharmacorezistant epilepsy. This bachelor thesis presents an overview of current knowledge about the modelling of epilepsy, while focusing on human in vitro models. Cell lines appear to be very promising in vitro models for modelling genetic epilepsies. For example, cell lines derived from human induced pluripotent stem cells or human neural stem cells, which both allow for introduction of potentially pathological mutations and further differentiation into many different cell types. Human in vitro models of epilepsy play important role in understanding the process of epileptogenesis, ictogenesis, mechanism of antiepileptic drugs effects and are used in the search for new active substances. Epilepsy comes with great burden of disease for the patients, that is why it is very important to research not only the molecular mechanisms of epileptogenesis, but also advancements of personalised therapy, which could give hope to many (even pharmacorezistant) patients.
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Effects of a neuroactive steroid on motor skills of young laboratory rat.
Košťálová, Tereza ; Mareš, Pavel (advisor) ; Valeš, Karel (referee)
The steroid substances with effect on nervous tissue are plenteously studied in last years. Their biggest benefits are especially anticonvulsant and anxiolytic effects. This thesis inspects the influence of newly discovered neruactive steroid pregnanolone pyroglutamate synthesized in The Institute of Organic Chemistry and Biochemistry of the Czech Academy of Science (IOCB CAS), which offer potential opportunity of a new therapy of epilepsy from actual pharmacokinetic results. Our goal was to detect, if this substance has any negative effects on locomotor skills of young laboratory rats. In theoretical part of the thesis the development of laboratory rat is briefly descibed, especially its motor skills and sensory functions in comparison with human. The process of the experiments and choice of especially motor skill tests are described in Metogology part. The results of experiment and its comparation with the effect of other neuromediators are introduced and discussed in the practical part of this thesis. There were no serious effects of pregnanolonepyroglutamate applied repeatedly in perinatal period on motor performance. Acute administration of the highest dose of PPG to 12-day-old rat pups resulted in prolongation of time in surface righting and negative geotxis tests. This data are positive for...
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