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. Author manuscript; available in PMC: 2016 Apr 1.
Published in final edited form as: Front Neuroendocrinol. 2015 Jan 9;37:43–51. doi: 10.1016/j.yfrne.2014.12.002

Figure 2.

Figure 2

Seasonal changes in number of ARC kisspeptin cells (A) and their inputs to GnRH neurons (B). A: The number of kisspeptin-immunoreactive (Kiss) neurons in the middle and caudal ARC is decreased during anestrous (* p<.001). Images show examples of sections through the caudal ARC immunostained for kisspeptin in ewes perfused during either the breeding season or anestrus. Ewes were ovariectomized and implanted with E2 (OVX+E) to control for seasonal variation in endogenous steroid levels. Note that the number of kisspeptin cells in the POA, another major kisspeptin population (76), does not change seasonally. Bar = 100 μm. B: The percentage of GnRH cells in the MBH that receive one or more kisspeptin (Kiss) close contacts was less in anestrous than in breeding season ewes (* p<.001); GnRH cells in the POA or anterior hypothalamic area (AHA) showed no significant seasonal differences. In addition, GnRH cells in the MBH and AHA had significantly fewer Kiss contacts per cell in anestrous than in the breeding season (data not shown). Images show examples of dual immunoperoxidase stained sections in which close contacts (e.g., arrows) are seen between kisspeptin terminals (blue-black) and GnRH somas (brown) in the MBH. Bar = 15 μm. (A and B modified from ref. 48)