Cytoarchitecture of Cerebellar Cortex: Fractal Analysis as a Method for Quantitative Studies

Abstract

In this study we aimed to assess the possibility of fractal analysis utilization for the quantitative studies of cytoarchitecture in neuromorphology, namely in the studies of cerebellar cortex. We have chosen box counting method for fractal analysis. As an object of study we have chosen granule cell layer of cerebellar cortex. To estimate the informativeness of fractal analysis in the studies of cytoarchitecture and to assess the impact of the influencing factors (cell size, cell density or cell number, and pattern of cell distribution) we created artificial models of granule cells composition in the cerebellar cortex. We submit a proposition to consider the cell clusters and their assemblages as a whole entity. The cytoarchitecture as a whole entity exhibits some fractal properties: self-similarity of different scales, irregularity of the spatial configuration. Fractal dimension is the measure of space filling degree, so the fractal dimension measured in cellular groups characterizes space filling degree of cell assemblages. We revealed that the space filling degree depends on cell size, cell density (cell number) and pattern of cell distribution and clusterization. Increase in cell size or/and cell density (cell number) results in the increase in Fractal dimension values. Fractal dimension values are higher when cells are distributed evenly than when cells form the clusters. While the size and density (relative number) of cells can be estimated using traditional morphometric methods, the pattern of cell arrangement is mainly qualitative, and the fractal analysis allows to quantitatively and comprehensively assessing the cytoarchitecture of brain cortex.