Celem pracy jest zbadanie możliwości sterowania przebiegiem procesów wewnątrz sieci neuronowej z pomocą zagnieżdżonych struktur neuronowych zgodnie ze schematem przedstawionym na rysunku 1. Położenie każdego neuronu przy trzecim stopniu zagnież-dżenia określać będą trzy pary współrzędnych {(x1,yl),(x2,y2),(x3,y3)}.
Apelin (APLN) is a new peptide which was initially gained from extracts of the bovine stomach mucous membrane. It has a few isoforms differing in length of polypeptide chain and biological activity. Apelin exerts a biological effect using a specific apelin receptor (APJ). At present, there is an increase of interest in this peptide and its receptor because they are specifically localized in the central nervous system (OUN). By means of immunohistochemical techniques it has been demonstrated that the majority of neurons contain APLN and some neurons along with oligodendrocytes and astrocytes accompanying them reveal a clear localization of the APJ receptor both in the white and grey matter of the spinal cord and brain. APLN can participate in the OUN’s development. It performs a function of neurotransmitter and neuromodulator as well as a regulator of synaptic conductivity. This peptide controls neuroendocrine mechanisms in the hypothalamus-pituitary axis. APLN regulates circadian rhythms as well as drinking and eating mechanisms in the pineal gland. In astrocytes APLN can exert neuroprotective activity and regulate astrocyte-neuron interactions. APLN’s influence on the functioning of glia and neurons through the APJ receptor has not been fully explained. Further examination can provide information about APLN’s role and its APJ receptor in normal and pathologically changed OUN.
Neuronów i sieci z nich zbudowanych, jako żywych, dynamicznych części organizmu, nie powinno się rozpatrywać w sposób statyczny. Tylko dynamiczny model, nie zawierający nadmiernych uproszczeń, może się okazać narzędziem użytecznym do celów badawczych. Wygodnym i łatwo dostępnym sposobem tworzenia takich modeli jest wykorzystywanie do tego celu szeroko znanych narzędzi, używanych obecnie do tworzenia sieci neuronowych dla potrzeb rozwiązywania przy ich pomocy różnych złożonych problemów. A ponieważ systemy do tworzenia sieci neuronowych powstały początkowo właśnie z ciekawości badaczy, chcących poznać strukturę i działanie mózgu, a dopiero potem były użyte do rozwiązywania problemów obliczeniowych - zabieg taki nazwano w tytule tej pracy "powrotem do korzeni". Należy mieć nadzieję, że metody i narzędzia do symulacji komputerowej sieci neuronowych, wyposażone w odpowiednią metodologię experiment in computo, staną się wkrótce dla neurobiologów narzędziem badawczym takim samym, jak oscyloskop rejestrujący impulsy naturalnych neuronów czy mikroskop pokazujący ich strukturę. Dane uzyskane na tej drodze są wprawdzie tylko aproksymacją rzeczywistości i wplecione są w iteracyjny ciąg składający się z zastosowania narzędzia komputerowego do interpretacji danych oraz uzyskiwania nowych danych na gruncie biologii, jednak i tak jest to jedno z najdoskonalszych narzędzi, jakie neurobiologia miała kiedykolwiek w swojej dyspozycji.
EN
Modelling of the human brain was the initial goal of the first applications of neural networks. Later it appeared, that artificial neural networks became a very useful and effective tool in modelling of complex problems in almost all domains. The objective of the work is the presentation of the results of research conducted nowadays in the field of the original applications of neural network approach, which were focused on modelling of brain functionality.
The aim of the study was to determine the existence and co-existence patterns of VIP and NPY in neurons and nerve fibers of porcine lumbar-sacral sympathetic chain ganglia. The studied ganglia were fixed with 4% buffered paraformaldehyde (perfusion) and then labeled by means of double-immunofluorescence using a mixture of antibodies cultivated in different species. The highest number of NPY-positive cells was observed in the lumbar ganglia and diminished in the direction of the caudal, where only single neurons were observed. In contrast, a different pattern of distribution was observed for VIP-positive neurons, whose number was higher in the more caudally located ganglia. Two populations of VIP-positive neurons could be distinguished: single, showing strong immunofluorescence and often with visible processes, located in the central part of the ganglia and a second population, composed of clusters of 4-8 cells and often co-localizing NPY. VIP-positive nerve fibers surrounded both NPY+ neurons and neurons lacking either NPY and/or VIP. The presence of a small number of NPY-positive neurons exhibiting very weak immunofluorescence in more caudally located SChG could suggest a "switch" of neuromediators produced there. An increase in the percentage of non-noradrenergic sympathetic neurons in more caudally located SChG may thus be implicative for a specific innervation pattern of target tissues of these ganglia.
The aim of the study was a quantitative and cytoarchitectonic examination of neurons of the ventral hippocampal CA1-CA4 fields in somatically mature female American mink (Neovison vison) (N = 6). Brains were removed and examined under a light microscope. The samples were stained by Nissl’s standard method, and histological samples were used for morphometric analysis. All ventral hippocampal CA1-CA4 fields were analyzed cytoarchitectonically and morphometrically with a calibrated image analysis system that consisted of a computer equipped with the Cell^D software Soft Imaging System (SIS) with an integrated digital camera Colorview IIIu (Soft Imaging System). Morphometric investigations of the pyramidal layer showed that the cells of the hippocampal CA1-CA4 fields in adult female American mink differ in size, shape, cell area, nucleus area and the nucleus-to-cell ratio (in%). The cells of the CA2 field were densely arranged, pyramidal and contained a small amount of cytoplasm; their size was differentiated. They were the largest in size (15.06 μm) and diameter (14.5 μm). The cells of the CA1 field had the smallest size (8.5 μm) and diameter (8.6 μm). In the CA3 field, small, densely packed neurons dominated, whereas neurons in the CA4 field formed a thin strand of loosely arranged cells. Given the increasing interest in hippocampal areas, it is necessary to continue studies of their morphology and morphometry in healthy animals and in those suffering from neurodegenerative diseases.