Mapping of cytoskeletal components in the hippocampal formation of the tree shrew (Tupaia belangeri)

The distribution of the major cytoskeletal components in frontal cryosectio ns of the hippocampal formation of adult male tree shrews (Tupaia belangeri ) was immunohistochemically investigated by using commercially available an tibodies. Actin-immunolabeling was evident in all layers of the dentate gyr us as well as in the regio superior (CA1) and the regio inferior (CA3). Neu rofilament 160 was detected only in the molecular layer of the dentate gyru s and in the axons of the granule cells (mossy fibers). For beta-tubulin, t he microtubule associated proteins (MAPs) MAP2AB, MAP2ABC and Tau, immunore activity was evident within the granule cells and within the somatodendriti c compartment of pyramidal neurons. Granule cells and the somata of the pyr amidal neurons were intensely labeled for kinesin. Our findings show the el aborate expression of cytoskeletal proteins in the hippocampal formation of the tree shrew, relatively similar to what is seen in other species but wi th also some important differences, such as the immunonegativity of the axo nal compartment for Tau in the tree shrew. which is contrary to what we see in the mouse (unpublished data). These findings provide useful insights re garding the organization of the hippocampal formation of the tree shrew and are fundamental for further research in this field. (C) 1999 Elsevier Scie nce B.V. All rights reserved.