The long distance effects of brain lesions: visualization of axonal pathways and their terminations in the human brain by the Nauta method.

This study aims at determining the reliability and the optimal post-injury survival time for the application of the Nauta technique to the analysis of the human brain. The Nauta method reveals the degeneration not only of nerve fibers, myelinated and unmyelinated, but also of their terminations. Immunohistochemical and ultrastructural observations appear to prove that the Nauta technique indeed stains axons in human autopsy material. The optimal survival time for the use of the Nauta method was found to be between nine days and five months. In cases with longer survival times--up to 20 months--the Nauta technique and a previously proposed polarizing technique (showing birefringent breakdown products of myelin) can be used as complementary methods. Applying these techniques to the human brain may help define the anatomical basis of neurological and neuropsychological symptoms important for man.