New parameters for analysis of changes microglial morphology using stereology and histomorphometry

Abstract

New parameters for analysis of changes microglial morphology using stereology and histomorphometryIn histological evaluation of experimental and pathological specimens, the degree of microglial activation is often evaluated on the basis of morphological features of the cells including the size and shape of the cells, the number and length of cell processes, as well as by increased expression of markers such as CD11b, CD45 (LCA) and Iba‐1. From stereological studies it is known that microglial activation is followed by proliferation of microglial cells and change in the morphology of the cells.To extend the list of morphological parameters that can be measured quantitatively for comparative studies, we combined digital image analysis and stereological methods for analysis of the morphology of microglia labeled by Iba‐1. In the molecular layer of fascia dentata of the hippocampus from 6 male C57Bl6‐mice the total number of microglial cells was 16 906 cells, the mean cell size was 151.3 µm3, and the average length of cell processes was 80.0 µm/cell. We found microglial cell bodies were ovoid in shape, as judged by the ratio of the shortest and longest diameter (ratio = 0.61) and that on average 5.65 cell processes were extending at the equatorial plane of the cell.