Morpho-quantitative stereological assessment of nerve fibers is a main research task in various biomedical disciplines, including neuroanatomy, neuropathology, neurosurgery and reconstructive microsurgery. In this paper, we will critically outline the modern approaches for nerve fiber quantitative assessment based on design-based 2D stereology and describe the principal morphological indicators of function loss and recovery that can be quantitatively assessed. Yet, the pros and cons of the main morphological techniques for investigating the structure and ultrastructure of axons in the peripheral nerves as well as in the optic nerve are given in appendix. This paper is directed towards all those basic and clinical researchers who wish to undertake the histomorphometrical study of peripheral and optic nerve in choosing the best morphological methods to meet their scientific goals.

peripheral nerve fibers, optic nerve, nerve regeneration, 2D-design-based stereology, osmium tetroxide, light microscopy, electron microscopy