Morphological feedback effect on neurons of the nucl. arcuatus (sive infundibularis) and nucl. subventricularis hypothalami due to gonadal atrophy.

We have correlated the light-microscopic features in the unmyelinated hypothalamus with gonadal atrophy in 15 women of 30-111 years of age and in 7 men between 29 and 82 years. In the postmenstrual cases there is a distinct concordance of gonadal atrophy and the manifestation of nucleolar changes (augmentation, multiplication and vacuolization) in many nerve cells of the arcuate and subventricular nuclei. In younger, still fertile women this nucleolar finding was seen only rarely and sporadically, was limited to the arcuate nucleus and was absent in the subventricular nucleus. We interpret this nucleolar finding as a feedback effect. In man, too, this coincidence is obvious with age and in gonadal atrophy, with fewer nucleolar changes in old age than are seen in women. This difference is probably caused by a more rapid drop of the estradiol than of the testosterone level. - The hypertrophy of the subventricular nucleus (Sheehan and Kovacs) was also observed in our postmenstrual cases.