Immunoelectron microscopic observation of the subcellular localization of kisspeptin
 neurokinin B and dynorphin A in KNDy neurons in the arcuate nucleus of the female rat

Hiroko Murakawa
Kinuyo Iwata
Toshiyuki Takeshita
Hitoshi Ozawa

KNDy neurons are named for their co-expression of three neuropeptides
 kisspeptin
 neurokinin B (NKB) and dynorphin A (DynA). These cells
 located in the hypothalamic arcuate nucleus (ARC)
 are associated with generation of gonadotropin-releasing hormone (GnRH)/luteinizing hormone (LH) pulses to control follicular growth and steroidogenesis. However
 subcellular sorting mechanisms for secretory vesicles containing these neuropeptides have not been elucidated. In this study
 we analyzed the localization pattern of kisspeptin
 NKB and DynA in the ARC of the ovariectomized rat immediately treated with estrogen using immunoelectron microscopy. First
 we identified neuropeptides by dual-labeled fluorescence immunohistochemistry
 with results indicating all three neuropeptides co-express within individual ARC cells in female rats. Next
 we investigated the subcellular localization pattern of kisspeptin
 NKB
 and/or DynA using post-embedding double immunoelectron microscopy
 indicating that each type of neuropeptide is contained within separate and individual neurosecretory vesicles. This suggests sorting and packaging of kisspeptin
 NKB and DynA is differentially regulated within KNDy neurons. Our findings facilitate understanding of regulatory mechanisms underlying kisspeptin secretion in KNDy neurons
 and generation of GnRH/LH pulses induced by kisspeptin in the ARC. (C) 2015 Elsevier Ireland Ltd. All rights reserved.

NEUROSCIENCE LETTERS

ELSEVIER IRELAND LTD

612

10.1016/j.neulet.2015.12.008

https://doi.org/10.1016/j.neulet.2015.12.008
https://www.ncbi.nlm.nih.gov/pubmed/26679227
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