Age and Long-Term Hormone Treatment Effects on the Ultrastructural Morphology of the Median Eminence of Female Rhesus Macaques

Michelle M. Naugle, Sateria A. Lozano, Fay A. Guarraci, Larry F. Lindsey, Ji E. Kim, John Morrison, William G.M. Janssen, Weiling Yin, Andrea C. Gore

Research output: Contribution to journalArticle

4 Citations (Scopus)

Abstract

The median eminence (ME) of the hypothalamus comprises the hypothalamic nerve terminals, glia (especially tanycytes) and the portal capillary vasculature that transports hypothalamic neurohormones to the anterior pituitary gland. The ultrastructure of the ME is dynamically regulated by hormones and undergoes organizational changes during development and reproductive cycles in adult females, but relatively little is known about the ME during aging, especially in nonhuman primates. Therefore, we used a novel transmission scanning electron microscopy technique to examine the cytoarchitecture of the ME of young and aged female rhesus macaques in a preclinical monkey model of menopausal hormone treatments. Rhesus macaques were ovariectomized and treated for 2 years with vehicle, estradiol (E2), or estradiol + progesterone (E2 + P4). While the overall cytoarchitecture of the ME underwent relatively few changes with age and hormones, changes to some features of neural and glial components near the portal capillaries were observed. Specifically, large neuroterminal size was greater in aged compared to young adult animals, an effect that was mitigated or reversed by E2 alone but not by E2 + P4 treatment. Overall glial size and the density and tissue fraction of the largest subset of glia were greater in aged monkeys, and in some cases reversed by E2 treatment. Mitochondrial size was decreased by E2, but not E2 + P4, only in aged macaques. These results contrast substantially with work in rodents, suggesting that the ME of aging macaques is less vulnerable to age-related disorganization, and that the effects of E2 on monkeys' ME are age specific.

Original languageEnglish (US)
Pages (from-to)650-664
Number of pages15
JournalNeuroendocrinology
Volume103
Issue number6
DOIs
StatePublished - Sep 1 2016
Externally publishedYes

Fingerprint

Median Eminence
Macaca mulatta
Hormones
Neuroglia
Haplorhini
Macaca
Therapeutics
Estradiol
Mitochondrial Size
Ependymoglial Cells
Organizational Innovation
Scanning Transmission Electron Microscopy
Anterior Pituitary Gland
Primates
Hypothalamus
Progesterone
Neurotransmitter Agents
Young Adult
Rodentia

Keywords

  • Aging
  • Estradiol
  • Glia
  • Hypothalamus
  • Median eminence
  • Mitochondria
  • Monkey
  • Progesterone

ASJC Scopus subject areas

  • Endocrinology, Diabetes and Metabolism
  • Endocrinology
  • Endocrine and Autonomic Systems
  • Cellular and Molecular Neuroscience

Cite this

Age and Long-Term Hormone Treatment Effects on the Ultrastructural Morphology of the Median Eminence of Female Rhesus Macaques. / Naugle, Michelle M.; Lozano, Sateria A.; Guarraci, Fay A.; Lindsey, Larry F.; Kim, Ji E.; Morrison, John; Janssen, William G.M.; Yin, Weiling; Gore, Andrea C.

In: Neuroendocrinology, Vol. 103, No. 6, 01.09.2016, p. 650-664.

Research output: Contribution to journalArticle

Naugle, MM, Lozano, SA, Guarraci, FA, Lindsey, LF, Kim, JE, Morrison, J, Janssen, WGM, Yin, W & Gore, AC 2016, 'Age and Long-Term Hormone Treatment Effects on the Ultrastructural Morphology of the Median Eminence of Female Rhesus Macaques', Neuroendocrinology, vol. 103, no. 6, pp. 650-664. https://doi.org/10.1159/000442015
Naugle, Michelle M. ; Lozano, Sateria A. ; Guarraci, Fay A. ; Lindsey, Larry F. ; Kim, Ji E. ; Morrison, John ; Janssen, William G.M. ; Yin, Weiling ; Gore, Andrea C. / Age and Long-Term Hormone Treatment Effects on the Ultrastructural Morphology of the Median Eminence of Female Rhesus Macaques. In: Neuroendocrinology. 2016 ; Vol. 103, No. 6. pp. 650-664.
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