Evidence for seasonal plasticity in the gonadotropin-releasing hormone (GnRH) system of the ewe: changes in synaptic inputs onto GnRH neurons.

@article{Xiong1997EvidenceFS,
  title={Evidence for seasonal plasticity in the gonadotropin-releasing hormone (GnRH) system of the ewe: changes in synaptic inputs onto GnRH neurons.},
  author={Jason Jie Xiong and Fred J. Karsch and Michael N Lehman},
  journal={Endocrinology},
  year={1997},
  volume={138 3},
  pages={1240-50}
}
In the Suffolk ewe, seasonal reproductive transitions are due primarily to changes in the responsiveness of the GnRH neurosecretory system to the negative feedback influence of estradiol. As GnRH neurons in the sheep, like those in other mammals, lack estrogen receptors, the influence of estradiol on GnRH neurosecretory activity is probably conveyed via afferents. As a possible structural basis for seasonality, we examined the ultrastructure and synaptic inputs of GnRH neurons in the preoptic… CONTINUE READING