AGE-RELATED MORPHOLOGICAL-CHANGES IN THE HIPPOCAMPUS IN 2 MOUSE STRAINS

The granule cell number (nGR) in the dentate gyrus (DG) has been repor ted to vary considerably among inbred strains of mice, thus providing proof of some genetically associated components to this variation. Fur thermore, several authors have described age-related morphological cha nges in the DG in both humans and animals, but there is no general agr eement in the literature about the occurrence of such changes. The pur pose of this study was to investigate for strain differences in hippoc ampal structure changes in old C57BL/6J (B) and DBA/2J (D) mice as com pared with younger ones. The nGR in the DG, as well as other structura l parameters of the hippocampus, were determined in female B and D mic e of 4 and 24 months. The two-way analysis of variance indicated a sig nificant interaction between 'strain' and 'age' for the nGR, suggestin g that this parameter changes differently with age in B and D mice. Th is finding indicates that these strains could present a differential s usceptibility in granule cell aging raising the possibility that age e ffects on the granule cell population in the DG could be influenced by some hereditary factors.