A confocal microscopic study of gonadotropin-releasing hormone (GnRH) neuron inputs to dopaminergic neurons containing estrogen receptor alpha in the arcuate nucleus of GnRH-green fluorescent protein transgenic mice.
The purpose of the present study was to determine whether the septo-preoptico-tuberoinfundibular gonadotropin-releasing hormone (GnRH) pathway comes in close juxtaposition with tyrosine hydroxylase immunoreactive (TH-IR) neurons in the arcuate nucleus of female mice. Immunohistochemical staining with a TH monoclonal antibody coupled with confocal microscopy was employed on vibratome-cut brain sections of female GnRH-green fluorescent protein (GFP) transgenic mice to evaluate possible appositions between GnRH and tuberoinfundibular dopaminergic (TIDA) neurons. TH-IR neurons of the arcuate nucleus received GnRH neuronal appositions in adult female mice at proestrus and estrus stages. In contrast, no GnRH appositions were observed in adult females at diestrus. Subsequently, double immunohistochemical staining for TH and estrogen receptor-alpha (ERalpha) was performed to examine the role of estradiol on this relationship. We found that most TH-IR neurons contacted by GnRH fibers were immunoreactive for ERalpha. Our observations suggest that GnRH neurons communicate directly with TIDA neurons in the adult female. Furthermore, ERalpha activation in TIDA neurons may be involved in the formation of connections between GnRH neurons and TIDA neurons.
Mitchell
Valerie
V
INSERM U422, Neuroendocrinology and Neuronal Physiopathology, Lille, France. mitchell@lille.inserm.fr
Loyens
Anne
A
Spergel
Daniel J
DJ
Flactif
Martial
M
Poulain
Pierre
P
Tramu
Gerard
G
Beauvillain
Jean-Claude
JC
D000818:Animals; D001111:Arcuate Nucleus of Hypothalamus / Q000737:chemistry* / Q000502:physiology; D001931:Brain Mapping; D004298:Dopamine / Q000032:analysis; D047628:Estrogen Receptor alpha; D005260:Female; D007987:Gonadotropin-Releasing Hormone / Q000032:analysis*; D049452:Green Fluorescent Proteins; D007031:Hypothalamus / Q000737:chemistry* / Q000502:physiology; D008164:Luminescent Proteins; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D018613:Microscopy, Confocal; D009415:Nerve Net / Q000033:anatomy & histology / Q000737:chemistry*; D009434:Neural Pathways / Q000033:anatomy & histology / Q000737:chemistry; D009474:Neurons / Q000737:chemistry; D011960:Receptors, Estrogen / Q000032:analysis; D014446:Tyrosine 3-Monooxygenase / Q000032:analysis*
D047628:Estrogen Receptor alpha; D008164:Luminescent Proteins; D011960:Receptors, Estrogen; D049452:Green Fluorescent Proteins; D007987:Gonadotropin-Releasing Hormone; D014446:Tyrosine 3-Monooxygenase; D004298:Dopamine