Functional analysis of prolactin-sensitive neural circuits in the arcuate nucleus.
Reproductive Medicine, Urology
Final Report Abstract
We visualized the prolactin-sensitive neural circuitry of the ARC and investigated different neuronal subpopulations found within this nucleus. Cryosections from PRLR reporter mice revealed the localization of cell bodies and axonal projections of the PRLR cells. We found a uniform distribution of PRLR cells throughout the ARC. We could also confirm the presence of prolactin-sensitive neuronal populations in a 3D model using iDISCO tissue clearing method. To analyze the projection networks of these neurons, both within and outside the ARC, we devised a viral transduction strategy. We stereotaxically injected AAV8-hSyn-DIO-mCherry in different regions of the ARC and utilized immunostaining to locate the presence of mCherry+ axons throughout the brain. We found that the PRLR neurons of the anterior ARC project to the MPOA, PVN and median eminence and to a smaller extent to the central ARC but not to the AVPV. PRLR neurons of the central Arc had the highest number of nuclei projection targets when compared to other arcuate regions. These neurons project to AVPV, MPOA, PVN, median eminence, and anterior and posterior ARC. We found the posterior ARC sends projections only to the PVN, central ARC and the median eminence. Due to the strong projections of PRL-sensitive neurons across all ARC regions to the circumventricular ME, we were interested in finding out whether prolactin-sensitive neurons in the ARC have access to blood-borne cues from the rest of the body. For this purpose, we intraperitoneally injected FluoroGold. Subsequent immunostaining on brain sections revealed that PRLR PVN and ARC neurons could take up FluoroGold from the circulation, while the MPOA and AVPV neurons could not. The anterior and central ARC showed a higher FluoroGold uptake (~80% FG+/GFP+) compared to the posterior ARC (~5% FG+/GFP+). Interestingly, within both the anterior and central ARC, this uptake was sexually dimorphic, with females showing a significantly higher number of GFP neurons containing FluoroGold. We have produced an AAV9-CAGS- DIO-BL-P2A-GFP virus to further investigate these innervation networks upstream and downstream of the prolactin-sensitive neuronal populations within the ARC in the future. Finally, we also further characterized different subpopulations of prolactin-sensitive neurons with the help of RNAScope. Out of 21 different neuropeptides that we screened for, we identified an Agrp-subpopulation in the posterior ARC, a Tac2-subpopulation in the central and posterior ARC, GABAergic and dopaminergic subpopulations in the central ARC and a GABAergic subpopulation in the anterior ARC.
Publications
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Widespread Cell-Specific Prolactin Receptor Expression in Multiple Murine Organs. Endocrinology, 160(11), 2587-2599.
Aoki, Mari; Wartenberg, Philipp; Grünewald, Ramona; Phillipps, Hollian R.; Wyatt, Amanda; Grattan, David R. & Boehm, Ulrich
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Prolactin-sensitive olfactory sensory neurons regulate male preference in female mice by modulating responses to chemosensory cues. Science Advances, 7(41).
Aoki, Mari; Gamayun, Igor; Wyatt, Amanda; Grünewald, Ramona; Simon-Thomas, Martin; Philipp, Stephan E.; Hummel, Oliver; Wagenpfeil, Stefan; Kattler, Kathrin; Gasparoni, Gilles; Walter, Jörn; Qiao, Sen; Grattan, David R. & Boehm, Ulrich
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Intra-pituitary follicle-stimulating hormone signaling regulates hepatic lipid metabolism in mice. Nature Communications, 14(1).
Qiao, Sen; Alasmi, Samer; Wyatt, Amanda; Wartenberg, Philipp; Wang, Hongmei; Candlish, Michael; Das, Debajyoti; Aoki, Mari; Grünewald, Ramona; Zhou, Ziyue; Tian, Qinghai; Yu, Qiang; Götz, Viktoria; Belkacemi, Anouar; Raza, Ahsan; Ectors, Fabien; Kattler, Kathrin; Gasparoni, Gilles; Walter, Jörn ... & Boehm, Ulrich
