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Discrimination of EMG signals from individual forearm muscles from surface EMG.
Krásná, Jana ; Otáhal, Jakub (advisor) ; Konopková, Renata (referee)
Title: Discrimination of EMG signals from individual forearm muscles from surface EMG Abstract: Location of electrodes for sensing the forearm muscles using surface electromyography is not accurately described. It is based only on recommendations by various authors in making researches. The aim of this study was to determine the optimal placement of electrodes on the forearm and describe it to another repeatable measurements. By analyzing the amplitude of EMG recording is confirmed not only the optimal location of electrodes, but either suggested muscle synergies that are possible to analyze more deeply in other studies because a detailed examination of muscle synergies are considerable application in upper limb prosthetics Keywords: Surface electromyography, forearm muscles, amplitude analysis
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Applications of multiple reference frames environments in behavioral research
Telenský, Petr ; Bureš, Jan (advisor) ; Němec, Pavel (referee) ; Otáhal, Jakub (referee)
This work has been motivated by the desire to enhance our knowledge about specific cognitive requirements of navigation in multiple reference frames environments and to understand the roles of the hippocampus and posterior parietal cortex in this behavior. The main conclusions of this thesis are: (a) We have developed a novel behavioral test called the Enemy Avoidance Task. The initial set of experiments has shown that laboratory rats are able to plan their movement with respect to a to-be-avoided moving object. Behavioral performance in the task may be quantitatively evaluated. (b) The aforementioned ability is crucially dependent on the functional integrity of the dorsal hippocampus. To the contrary, functional inactivation of the dorsal hippocampi by local infusion of tetrodotoxin did not cause any impairment in the ability of the animal to estimate its distance from a non-moving object. The finding suggests a specific role of the hippocampus in dynamic cognitive processes required for flexible navigation strategies such as continuous updating of information about the position of a moving stimulus. These results are at odds with the two major theories of hippocampal function (Cognitive map theory and Declarative memory theory) and therefore suggest that revision of the theories is necessary. (c)...
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Recruitment curve of H reflex in dignastics of radiculopathies.
Hrušková, Marcela ; Otáhal, Jakub (advisor) ; Ostrý, Svatopluk (referee)
Název práce: Náborová křivka H-reflexu v diagnostice radikulárních syndromů Cíle práce: Ověření spolehlivosti vyšetření náborové křivky H-reflexu a M-vlny diagnostice kompresivní radikulopatie Metody práce: U 24 osob s jednostranným kořenový syndromem S1 byl vyšetřen H-reflex m. soleus oboustranně bipolární stimulací n.tibialis v popliteální jamce. Elektromyografický signál byl digitalizován a následně byla hodnocena data pro asymptomatickou a symptomatickou končetinu. Hodnoceny byly prahy pro vyvolání H-reflexu a M-vlny, latence a amplitudy H-reflexu a M-vlny, strmost náborové křivky, její maxima Hmax. a Mmax. a poměr Hmax/Max . Tyto hodnoty pro symptomatickou stranu a asymptomatickou stranu byly statisticky porovnány. Výsledky: Výsledky měření potvrdily, že vyšetření náborové křivky H-reflexu je vhodnou diagnostickou metodou k objektivizaci radikulopatie S1. Na symptomatické straně došlo k signifikantnímu poklesu Mmax., Hmax, poměru Hmax/Mmax a sklonu náborové křivky H-reflexu. Klíčová slova: radikulopatie, EMG, H-reflex, M-vlna, náborová křivka
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Nitric oxide and its role in neurophysiology
Dobrovodská, Gabriela ; Otáhal, Jakub (advisor) ; Brime, Tufikameni (referee)
Title: Nitric oxide and its neurophysiologic role Objectives: The main aim of my diploma work is to evaluate the role of nitric oxide and its effects during epileptic seizure in rats. I summarize the present knowledge about nitric oxide and its effects on human organism in the theoretical section of this paper and I will suppose the positive effect of nitric oxide inhibitor in epileptic seizures in rats by the realization of my experiment. Methods: The experiment will be performed in the laboratory of Academy of Science of Czech Republic. Implementation will come through examining a set of ten rats. The first six will be given v (L-NPA) in an amount of 0,5mg to one side, which will take place by applying bilaterally to coele. Then after ten minutes 0,5µl of 4-aminopyridine (4-AP) will be applied bilaterally to coele. The control group, consisting of four rats will be given saline instead of L-NPA. The experiment will run for two days. Results: The course of epileptic seizure with application of L-NPA to examined group was compared with the control group. The experiment confirmed the positive effect of L-NPA in terms of delay and reduction of seizure. Keywords: nitric oxide, Nω -propyl-l-arginine, neurovascular coupling, 4-anopyridine, epilepsy
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H reflex during pasive movements
Borský, Ondřej ; Otáhal, Jakub (advisor) ; Michalec, Radim (referee)
Title: Motoneuron excitability depending on the level of muscle stretch Aim: The aim of this thesis is to evaluate if passive muscle lenght change may influence parameters of H - reflex of soleus muscle Method: Tibial nerve stimulation in the fossa poplitea area was performed on 6 persons while passive stretching or lengthening of the muscle. Action potentials were captured on soleus muscle. Stimulation was performed in three different time periods - 4s, 2s, 1s. Each period was performed twice. First in passive muscle stretching then the passive shortening. The Hmax and Mmax values during passive muscle stretching and shortening were evaluated and compared. Results: The measurment results showed that there was a significant decrease in the Hmax values during passive muscle stretching. Mmax values were evaluated as passive muscle length change independent. Keywords: EMG, recruitment curve, H-reflex, M-wave, m.soleus, excitability
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Effect of surface electrode type on quality of decopmposition of surface EMG signal
Strusková, Edita ; Otáhal, Jakub (advisor) ; Michalec, Radim (referee)
Title: Effect of surface electrode type on quality of decomposition of surface EMG signal Objectives: The aim of this thesis is to evaluate the effect of surface electrode type, which was used for EMG record, on the quality of decomposition of surface EMG signal using decomposition software EMGlab. Methods: The form of the thesis is an experimental essay. It was detected an EMG signal from one healthy volunteer during mild cyclic contraction. It was used three different types of electrodes (standard surface electrode, tetrode, tetrode with saw-off spikes) for EMG signal detection. These signals were decomposed in program EMGlab. The results were processed in program MS Excel, compared with each other and graphically displayed. Results: The measurement verified a hypothesis which claimed that the used type of electrode affects the quality of automatic decomposition. The best results of automatic decomposition provide the signal gained from the standard surface electrode. Key words: action potential, decomposition, surface electrodes, EMG signal, tetrode, electromyography
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Impairment of cellular metabolism as common pathophzsiological mechanism of CNS diseases
Hasala, Ondřej ; Otáhal, Jakub (advisor) ; Konopková, Renata (referee)
Name of thesis: Impairment of cellular metabolism as common pathophysiological mechanism of CNS diseases Problem definition: Every human cell needs energy for living. If the prodcution of ATP (as an universal energy carrier) is broken, cell restricts its activity first and during longterm depletion of ATP, dies. It was found, that cellular metabolism is broken in most pathologies in CNS. Disorder of respiratory chain by free radicals is the best known at Parkinson's disease, epilepsy, brain ischemia etc. Mitochondria, where respiratory chain is situated, is not only the aim of free radicals, but it is their major producer. The activity of respiratory chain decreases during the life and this phenomenan is called aging. Aim of thesis: To determine whether there is increased production of free radicals in mitochondria of rat (LE Wistar) hippocampus during the epileptic seizure. Method: Thesis involves experiment which was done with acute rat hippocampal slices. To induce epileptic seizure it was used 4-aminopyridine model. It was used fluorescence imaging as imaging method. Changes of superoxide production was detected with MitoSOX. Electrophysiological record was taken by programme Spike 2 with stimulation and recording electrode inside the slice. Results: There was no significant difference between...
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Changes in motor function and seizure susceptibility after photothrombic ischemic stroke in immature rat
Brima, Tufikameni ; Otáhal, Jakub (advisor) ; Kittnar, Otomar (referee) ; Dylevský, Ivan (referee)
i | P a g e ABSTRACT Changes in motor function and seizure susceptibility after photothrombic ischemic stroke in immature rat Perinatal stroke is a common cerebrovascular disorder affecting one in every 4000 births, typically associated with sequelae that include motor and cognitive deficits and long term comorbidities including epilepsy. We sought to determine the effect of perinatal induced stroke on motor function and seizure susceptibility in rats. Photothrombotic model of stroke was used in rat at postnatal day 7. Firstly we induced ischemic lesions of different extends to assess the consequences of stroke on motor function, locomotion and its correlation to morphological changes after stroke. To this end, paradigms sensitive to sensorimotor changes were used; histological changes were also assessed. Secondly, with the use of pure cortical lesions, seizure susceptibility in PTZ elicited models of epileptic seizures was analysed. For seizure occurrence, latency and severity, two different concentrations of PTZ (60 and 100 mg/kg) were administered subcutaneously in two different age groups at P 12 and P 25. In addition, episodes of rhythmic EEG activity were registered at P 25 following successive 20- and 40-mg/kg doses of PTZ administered interperitonealy. Our data depicted two kinds of lesions with...
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Will an increase in body temperature during status epilepticus in rat pups affect the extent and nature of damage to the hippocampus?
Chott, Robert ; Kubová, Hana (advisor) ; Otáhal, Jakub (referee)
Febrile seizures are epileptic seizures, arising in connection with febrile conditions in children of prechool age. In adults with epilepsy is often present a history of febrile status epilepticus, seizure whose duration is longer than 20 minutes. To study the role of febrile status epilepticus (FSE) in the development of epilepsy and neuronal damage, it is necessary to have a relevant animal models. This work is focused on the morphological analysis of the new created model of febrile status epilepticus, using a combination of short-term hyperthermia and chemical induced status epilepticus at 10 days old rats. In adulthood, the animals were examined by video/EEG monitoring, and then morphometric analysis. The aim of this study was to determine the importance of short-term hyperthermia during SE for neuropathological changes using stereological measurements of hippocampal volume.
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Numerical simulation of cerebrospinal fluid transport
Žáček, Petr ; Maršík, František (advisor) ; Otáhal, Jakub (referee)
Modelling of cerebrospinal fluid flow is important for understanding its influence on central nervous system, especially spinal cord. One of the reasons for its study is a disease called syringomyelia that probably develops as a result of severance of neural pathways by bubbles emerging during the propagation of pressure (expan- sion) disturbances through spinal cord and its surroundings. It is characterized by fluid-filled cavities in spinal cord. In this thesis, a model of fluid-filled co-axial elastic tubes is proposed that can help us simulate pressure disturbances propa- gation through spinal cord including its interactions and possible increase as the result of interferences or reflection. We derive quasi-one-dimensional governing equations in the form of nonlinear hyperbolic system of conservational laws and with its numerical solution by two-step Lax-Wendroff method with added artifi- cial viscosity we can quantitatively estimate almost twofold increase of pressure difference. 1
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