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

Abstract

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.

G‐protein coupled estrogen receptor, estrogen receptor α, and progesterone receptor immunohistochemistry in the hypothalamus of aging female rhesus macaques given long‐term estradiol treatment

“…It is not known, however, how density of populations of hypothalamic cells may play out as functional changes in responsiveness to steroid hormones. Furthermore, our observation of age‐related GPER‐IR cell hypertrophy is consistent with other hypertrophic neuronal populations in humans and monkeys including kisspeptin and neurokinin B (Ule et al, ; Rance et al, ; Rometo and Rance, ; Rance, ). In nonhuman primates, these data suggest that, following long‐term cyclic E 2 , ERα and PR in the PERI and ARC probably do not contribute significantly to an age‐related decline in hormone sensitivity.…”

Changes in Estrogen Receptor-α and -β in the Infundibular Nucleus of the Human Hypothalamus Are Related to the Occurrence of Alzheimer’s Disease Neuropathology

“…1, A-C). Nucleolar augmentation, multiplication, and vacuolization has been described earlier in the nerve cells of the subventricular part of the infundibular nucleus in postmenopausal women and hypergonadotropic hypogonadal women, whereas in younger, still-fertile women, these manifestations were only rarely present in the infundibular nucleus and were absent in the subventricular nucleus (96). These nucleolar changes remain visible up to the age of 111 yr.…”

“…These nucleolar changes remain visible up to the age of 111 yr. In elderly men, far fewer nucleolar changes were present than observed in postmenopausal women (96). The nucleolus is a membraneless organelle within the nucleus whose major function is ribosome biogenesis (97).…”

Stereologic study of the hypothalamic infundibular nucleus in young and older women

“…A variety of measurements indicate that neuronal hypertrophy reflects increased neuronal activity. For example, in older women, the hypertrophied neurons display larger nuclei and nucleoli, increased Nissl substance (Sheehan and Kovács, 1966; Ule et al, 1983; Rance et al, 1990), and elevated tachykinin mRNAs (Rance and Young, 1991). Castration‐induced hypertrophy of neuroendocrine neurons in the rat arcuate nucleus is accompanied by significant increases in dendrite length, dendrite volume, terminal branch number, and dendritic spines (Danzer et al, 1998).…”