Androgen-dependent Stimulation of Brain Dopaminergic Systems in the Female European Eel (Anguilla Anguilla).
From: Unité Scientifique de Muséum 0401, Centre National de la Recherche Scientifique/MNHN/UPMC Biologie des Organismes Marins et Ecosystèmes Département des Milieux et Peuplements Aquatiques, Muséum National d’Histoire Naturelle, 75231 Paris, France.
Endocrinology
- Publish Date: Jun 2006
- ISSN: 0013-7227
- Volume: 147
- Issue: 6
- Pages: 2964-73
- Medium: Print
- Language: English
- Citation (JAMA): Weltzien Finn-Arne, Pasqualini Catherine, Sébert Marie-Emilie, et al. Androgen-dependent Stimulation of Brain Dopaminergic Systems in the Female European Eel (Anguilla Anguilla).. Endocrinology Jun 2006;147:2964-73
Abstract
Dopamine (DA), a neurotransmitter present in all vertebrates, is involved in processes such as motor function, learning and behavior, sensory activities, and neuroendocrine control of pituitary hormone release. In the female eel, we analyzed how gonadal steroids regulate brain expression of tyrosine hydroxylase (TH), the rate-limiting enzyme in the biosynthesis of DA. TH mRNA levels were assayed by quantitative real-time RT-PCR. TH-positive nuclei were also localized by in situ hybridization (ISH) and immunohistochemistry, and the location of TH nuclei that project to the pituitary was determined using 1,1’-dioctadecyl-3,3,3’,3’-tetramethylindicarbocyanine perchlorate retrograde tracing. Chronic in vivo treatment with testosterone increased TH mRNA specifically in the periglomerular area of the olfactory bulbs and in the nucleus preopticus anteroventralis (NPOav). NPOav was labeled with 1,1’-dioctadecyl-3,3,3’,3’-tetramethylindicarbocyanine perchlorate, showing that this nucleus is hypophysiotropic in the eel. The nonaromatizable 5alpha-dihydrotestosterone gave identical results in both areas, whereas 17beta-estradiol had no stimulatory effect, showing that the observed stimulatory effects of testosterone were androgen dependent. In teleosts, DA neurons originating from the NPOav directly inhibit gonadotropic function, and our results indicate an androgen-dependent, positive feedback on this neuroendocrine control in the eel. In mammals, DA interneurons in the olfactory bulbs are involved in the enhancement of olfactory sensitivity and discrimination. Our results in the European eel suggest an androgen-dependent stimulation of olfactory processing, a sensory function believed to be important in eel navigation during its reproductive migration toward the oceanic spawning grounds. To our knowledge, this is the first evidence from any vertebrate of an androgen-dependent effect on DAergic activity in the olfactory bulbs, providing a new basis for understanding the regulation by gonadal steroids of central DAergic systems in vertebrates.
Mesh Headings (Keywords): Anguilla, Animals, Brain, Dopamine, Estradiol, Female, Gene Expression Regulation, Enzymologic, In Situ Hybridization, Olfactory Bulb, Preoptic Area, RNA, Messenger, Reverse Transcriptase Polymerase Chain Reaction, Testosterone, Tyrosine 3-Monooxygenase
Check for Full Text / PubMed Unique Identifier (PMID): 16543374
This abstract is part of PubMed, a service of the U.S. National Library of Medicine. PubMed includes more than 17 million citations from MEDLINE and other life science journals for biomedical articles. See Copyright and Disclaimers.
Linked medical terms appearing on this page are added by Healia to help readers find more information and are not part of the original PubMed document.
The data herein was last updated on July 8th, 2008 and may not reflect the most current and accurate data available from NLM.