Use of the Glees Silver Technique in the Hypothalamus

Abstract

ONE of the most important advances in technical procedures for determining the course and distribution of fibre tracts in the central nervous system is the method based on the recognition of terminal degeneration by silver impregnation. As the authors of these methods have emphasized, however, they need to be used with care and discrimination in order to avoid possible fallacies of interpretation. We have recently observed that in certain (but not all) of the cell groups of the hypothalamus and preontic region in a number of normal brains (human and macaque monkey) stained by the Glees technique, the appearance of apparently typical terminal degeneration is present. This is particularly the case with the dorso-medial and ventromedial hypothalamic nuclei. The reason why these nuclei should show this appearance of ‘degeneration’ is not clear; but it may be related to the peculiar metabolic activities which are known to modify the appearance of axons in some of the hypothalamic nuclei. This observation is of importance since it is probable that some investigators have, in the past, mistaken this appearance seen in sections of normal brains for true terminal degeneration, and on this basis have described fibre connexions with widely different parts of the brain.