title: A subpopulation of gonadotropin-releasing hormone neurons in the adult mouse forebrain is γ-Aminobutyric acidergic.
abstract: Gonadotropin-releasing hormone (GnRH) neurons play a pivotal role in reproductive function. GnRH is released in distinct pulses that are regulated by neurotransmitters or neuromodulators. With immunohistochemistry and GAD67-GFP knockin mice, this study shows for the first time that a subset of GnRH neurons in the forebrain of adult mouse is γ-aminobutyric acid (GABA)-ergic. There is a gender difference in the percentage of GnRH neurons expressing GAD67-GFP in female vs. male mice. The percentage of GnRH neurons expressing GAD67-GFP decreased after castration of female mice and increased to the normal female level after estradiol treatment. The percentage of GnRH neurons expressing GAD67-GFP did not change significantly in intact, castrated, or castration + testosterone propionate-treated male mice. During the female estrous cycle, the percentage of GnRH neurons expressing GAD67-GFP was higher during the estrous stage than during the diestrous stage. During sexual maturation of postnatal development, GnRH neurons did not express GAD67-GFP until postnatal day (P) 15, and the gender differences were first detected at P30, which corresponds to the maturation stage. In conclusion, our data suggest that 1) a subset of GnRH neurons in mouse forebrain is GABA-ergic, 2) expression of GAD67-GFP in GnRH neurons is at least in part regulated by estrogen, and 3) GnRH neurons secrete GABA to regulate themselves.
authors.affiliation: Department of Neurobiology, Key Laboratory of Molecular Neurobiology, Ministry of Education, Second Military Medical University, Shanghai, People's Republic of China.
authors.forename: Jiao
authors.initials: J
authors.lastname: Zhu
authors.affiliation: School of Life Science, Shanghai University, Shanghai, People's Republic of China.
authors.forename: Xiao-hui
authors.initials: XH
authors.lastname: Xu
authors.affiliation: Autonomic Neuroscience Centre, University College Medical School, London, United Kingdom.
authors.forename: Gillian E
authors.initials: GE
authors.lastname: Knight
authors.affiliation: Department of Neurobiology, Key Laboratory of Molecular Neurobiology, Ministry of Education, Second Military Medical University, Shanghai, People's Republic of China.
authors.forename: Cheng
authors.initials: C
authors.lastname: He
authors.affiliation: Autonomic Neuroscience Centre, University College Medical School, London, United Kingdom.|Department of Pharmacology and Therapeutics, The University of Melbourne, Melbourne, Australia.
authors.forename: Geoffrey
authors.initials: G
authors.lastname: Burnstock
authors.affiliation: Department of Neurobiology, Key Laboratory of Molecular Neurobiology, Ministry of Education, Second Military Medical University, Shanghai, People's Republic of China.
authors.forename: Zhenghua
authors.initials: Z
authors.lastname: Xiang
mesh_terms: D000367:Age Factors; D000818:Animals; D000831:Animals, Newborn; D002369:Castration; D004958:Estradiol / Q000494:pharmacology; D005260:Female; D018507:Gene Expression Regulation, Developmental / Q000187:drug effects / Q000235:genetics; D005968:Glutamate Decarboxylase / Q000235:genetics / Q000378:metabolism; D007987:Gonadotropin-Releasing Hormone / Q000378:metabolism*; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D009474:Neurons / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D016548:Prosencephalon / Q000166:cytology*; D043343:Testosterone Propionate / Q000494:pharmacology; D005680:gamma-Aminobutyric Acid / Q000378:metabolism*
chemical_list: D049452:Green Fluorescent Proteins; D007987:Gonadotropin-Releasing Hormone; D004958:Estradiol; D005680:gamma-Aminobutyric Acid; D005968:Glutamate Decarboxylase; C402565:glutamate decarboxylase 1; D043343:Testosterone Propionate
keywords: GAD67; GnRH neuron; brain; mouse; sex hormone