Estradiol affects axo-somatic contacts of neuroendocrine cells in the arcuate nucleus of adult rats

Neuroscience. 2003;117(4):791-4. doi: 10.1016/s0306-4522(02)00967-3.


It has been shown that gonadal steroids have the capacity to induce synaptic plasticity in certain areas of the nervous system. Previously we have demonstrated that due to the effect of estradiol there is a transient decrease in the number of GABAergic axo-somatic synapses in the arcuate nucleus. By using systemic application of the tracer Fluorogold we retrogradely labeled a subpopulation of arcuate neurons that project to the median eminence. We than applied the disector method for synapse quantification and found that these "hypophysiotropic neurons" receive less axo-somatic inputs. We found that 17beta-estradiol induced a decrease in the numerical density of axo-somatic contacts of these retrogradely-labeled neoroendocrine cells. Our data support the hypothesis that the hormonally driven morphological synaptic plasticity is neuron specific within the arcuate nucleus and plays a decisive role in the regulation of anterior pituitary.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Arcuate Nucleus of Hypothalamus / drug effects
  • Arcuate Nucleus of Hypothalamus / metabolism*
  • Arcuate Nucleus of Hypothalamus / ultrastructure
  • Cell Count
  • Estradiol / metabolism*
  • Estradiol / pharmacology
  • Female
  • Fluorescent Dyes
  • Immunohistochemistry
  • Median Eminence / physiology
  • Microscopy, Electron
  • Neural Pathways / drug effects
  • Neural Pathways / metabolism*
  • Neural Pathways / ultrastructure
  • Neuronal Plasticity / drug effects
  • Neuronal Plasticity / physiology*
  • Pituitary Gland, Anterior / physiology
  • Presynaptic Terminals / drug effects
  • Presynaptic Terminals / metabolism*
  • Presynaptic Terminals / ultrastructure
  • Rats
  • Rats, Sprague-Dawley
  • Stilbamidines*


  • 2-hydroxy-4,4'-diamidinostilbene, methanesulfonate salt
  • Fluorescent Dyes
  • Stilbamidines
  • Estradiol