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Cellular scaling roles for passerine brains
Kocourek, Martin ; Němec, Pavel (advisor) ; Kratochvíl, Lukáš (referee)
Many passerine birds, particularly corvids, are known to express complex cognitive skills comparable to those observed in primates. In order to examine how these similarities are reflected at the cellular level, I counted neurons and nonneuronal cells in passerine brains using the isotropic fractionator method. I show that, in these birds, neuronal numbers scale almost isometrically with telencephalic size, i.e., the average neuron size shows little increase and neuronal density decreases minimally as brains get larger. Neuronal densities in the passerine telencephalon exceed those observed in the primate cerebral cortex by a factor of 3-6. As a result, the number of telencephalic neurons in the Common Raven (Corvus corax) equals those observed in the cerebral cortex of small monkeys. The cerebellum features similar scaling rules. However, because the relative size of the cerebellum is smaller than in mammalian brains, cerebellar neurons make a much smaller proportion of total brain neurons than in mammals. In contrast to the little variation in neuronal densities in telencephalon and cerebellum, the density of neurons rapidly decreases with increasing structure size in the diencephalon, optic tectum and brain stem. For all examined brain structures, the densities of nonneuronal cells remain constant...
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Cerebral laterality in birds and mammals, its behavioral correlation and evolutionary significance
Tureček, Petr ; Komárek, Stanislav (advisor) ; Němec, Pavel (referee)
Lateralization of brain is ubiquitous quality of vertebrate brain. In this paper we rewiev examples of brain lateralization in birds and mammals and it's behavioral impacts. Than we discuss possible evolutionary origins of these asymmetries and their evolutionary significance. We try to explain individual as well as population level lateralization. We propose, that population level lateralization can, in principle, arise just on the genofondal basis, if the organism itself contributes to the enviroment with the lateralized behavior. Lateralized sensory input on the other hand should stand on the advantages of synchronizing with other individuals due to the disatvantage of predictability of lateralized population. Keywords: Lateralization; laterality; population level lateralization; asymmetry; evolutionary significance
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Methodological aspects of active place avoidance task
Bahník, Štěpán ; Stuchlík, Aleš (advisor) ; Němec, Pavel (referee)
The active place avoidance task represents one of the methods of the study of animal cognition. In this task, a subject is put on a rotating circular arena and avoids invisible sector that is stable with respect to the room. Rotation of the arena means that the subject's avoidance must be active, otherwise the subject would be moved in the punished sector by the rotation of the arena and a slight electric shock would be administered. The experiment described in the present work explored the effect of variable arena rotation speed on the ability to avoid the punished sector. Rats in a group with a variable arena rotation speed learned to avoid the punished sector with the same speed and attained the same ability to avoid the sector as rats in a group with a stable arena rotation speed. The only difference between the two groups was found in a preferred position within the room. No difference was found between the two groups in the dark phase, where the rats could not use orientation cues in the room. Only one rat was able to learn the avoidance of the punished sector in this phase. The results of the experiment suggest that idiothetic orientation and interval timing are not crucial for learning of the avoidance of the punished sector. However, idiothetic orientation is sufficient for the avoidance of the...
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Depth map by using Kinect
Němec, Pavel ; Kaller, Ondřej (referee) ; Boleček, Libor (advisor)
Nowadays, depth maps are widely used in various branches of human activity (in building industry, medicine, mechanical engineering, robotics, show business etc.). The aim of this thesis is to get acquainted with different methods of their acquisition and with possibilities of their enhancement (e.g. reduction of noise and points of not specified depth). The main subject of this research are depth maps acquired by Kinect device.
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Proposal of Internet Promotion for E-commerce Solution
Němec, Pavel ; Kaňka, Mirek (referee) ; Luhan, Jan (advisor)
This master thesis deals with the issue of online promotion for a particular group of online shops. The first part deals with the clarification of concepts that are closely related to the given issue. The second part analyzes the current promotion of internet shops. In the design section there are several sub-proposals that lead to the improvement of e-shop promotion.
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Creation of Logistic Concept in the Selected Company
Němec, Pavel ; Basel, Martin (referee) ; Jurová, Marie (advisor)
The master’s thesis is focused on the issue of logistic concept in the company BKR ČR, s. r. o. It provides a theoretical background for the topic and observes the current situation in the company. Proposed measures are based on the critical analysis in order to increase efficiency and effectiveness of company logistics and customer satisfaction.
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Factors affecting oetrous cycles in the house mouse (Mus musculus)
Havrdová, Leona ; Stopka, Pavel (advisor) ; Němec, Pavel (referee)
Factors affecting oetrous cycles in the house mouse (Mus musculus) Abstract This bachelor thesis deals with factors which have significant influence on house mouse (Mus musculus) oestrous cycle. Main theme is oestrous cycle modulation caused by male or female chemical signals. Familiar phenomena like Bruce effect, Whitten effect and Lee-Boot effect are described in detail along with newly explored social modulation issues (ovulation trigger, male genotype role etc.). Environmental impact is also included, especially role of Bisphenol A in connection with negative impacts on human reproduction (tested on mice). Key words: oestrus, pheromone, MUP, Mus musculus, vomeronasal organ
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Immediate early genes as a tool for study of spatial orientation and memory
Bláhová, Veronika ; Němec, Pavel (advisor) ; Telenský, Petr (referee)
Properties of the environment, spatial orientation cues and time-shifting movements are essential for cognitive maps. The understanding of how both space and the animal's position within that space are represented in the brain has been significantly advanced by the discoveries of four principal neuronal types: the place cells, the head direction cells, the grid cells and border cells. Their activity being driven by both allothetic (visual and non-visual landmarks), and idiothetic cues (internal movement cues based on proprioceptive and vestibular information). Brain regions containing aforementioned types of neurons constitute complex spatial representation system. Immediate early genes (IEGs) and their products became sophisticated tool for the study of neural substrate of spatial orientation including magnetic orientation. For further research it is unavoidable to uncover the dynamic of processes related to IEGs in order to better understanding the functions of brain centres involved in rodent navigation circuit. This work summarises our knowledge about spatial orientation of the vertebrates aimed at rodents, in context with detection of IEGs expression as activity markers in neural substrate. There are described most common experimental mazes and most frequent detection methods used in connection with...
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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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Enamel cover of the mammalian teeth: structural, functional, developmental and phylogenetic aspects.
Hanousková, Pavla ; Horáček, Ivan (advisor) ; Němec, Pavel (referee)
Specificities of the mammalian teeth and their enamel coat with particular re- spect to the autapomorphies establishing the mammalian organization. Basic structural and organizational levels of the enamel histology (nanocrystals, elementary crystallites, prismatic enamel, IPM, schmelzmuster, ultimate characteristics of particular dentitions). Basic survey of comparative data: characterization of enamel of mammals in particular clades and a brief summary of their specificities. Concluding remarks on current state of knowledge and per- spectives of further study. 1
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