Morphometric investigations of the glial cell nests in the rhinencephalic allocortex of the dog
Abstract
The glial cell nests in the rhinencephalic allocortex in dogs were investigated in order to elucidate their involvement in glioma formation and to assess age-dependent changes. The glial cell nests are made up of cells with medium-sized dark nuclei and of cells with large pale nuclei. The volume of the whole brain, the allocortex and the glial cell nests were estimated following Cavalieri's principle. Unbiased estimates of the numerical densities and total numbers of the two prevailing cell populations within these nests were obtained using the optical disector.
With increasing age, the volume fraction of the glial cell nests of the allocortex was significantly decreased as was the numerical density and the total number of cells with medium-sized dark nuclei. In contrast, the numerical density and the total number of cells with large pale nuclei was significantly increased. There was no significant difference in any of the measured parameters between dolichocephalic and brachycephalic dogs, the latter showing a predisposition for glioma formation.
The combination of Cavalieri’s principle and optical disector proved to be a very efficient morphometric tool to estimate volumes, numerical densities, and total cell number. The significance of the age-dependent changes remains just as obscure as does the function of the glial cell nests. The glioma disposition of the brachycephalic dog cannot be explained with the data of our study.