title: Localization of reelin signaling pathway components in murine midbrain and striatum.
abstract: We investigated the distribution patterns of the extracellular matrix protein Reelin and of crucial Reelin signaling components in murine midbrain and striatum. The cellular distribution of the Reelin receptors VLDLr and ApoER2, the intracellular downstream mediator Dab1, and the alternative Reelin receptor APP were analyzed at embryonic day 16, at postnatal stage 15 (P15), and in 3-month-old mice. Reelin was expressed intracellularly and extracellularly in midbrain mesencephalic dopaminergic (mDA) neurons of newborns. In the striatum, Calbindin D-28k(+) neurons exhibited Reelin intracellularly at E16 and extracellularly at P15 and 3 months. ApoER2 and VLDLr were expressed in mDA neurons at E16 and P15 and in oligodendrocytes at 3 months, whereas Dab1 and APP immunoreactivity was observed in mDA at all stages analyzed. In the striatum, Calbindin D-28k(+)/GAD67(+) inhibitory neurons expressed VLDLr, ApoER2, and Dab1 at P15, but only Dab1 at E16 and 3 months. APP was always expressed in mouse striatum in which it colocalized with Calbindin D-28k. Our data underline the importance of Reelin signalling during embryonic development and early postnatal maturation of the mesostriatal and mesocorticolimbic system, and suggest that the striatum and not the midbrain is the primary source of Reelin for midbrain neurons. The loss of ApoER2 and VLDLr expression in the mature midbrain and striatum implies that Reelin functions are restricted to migratory events and early postnatal maturation and are dispensable for the maintenance of dopaminergic neurons.
authors.affiliation: Institute for Anatomy and Cell Biology, Department of Molecular Embryology, Albert-Ludwigs-University Freiburg, Albertstrasse 17, 79104, Freiburg, Germany.|Department of Histology and Cytology, Faculty of Veterinary Medicine, Zagazig University, Zagazig, 44519, Egypt.
authors.forename: Ahmed
authors.initials: A
authors.lastname: Sharaf
authors.affiliation: Institute for Anatomy and Cell Biology, Department of Molecular Embryology, Albert-Ludwigs-University Freiburg, Albertstrasse 17, 79104, Freiburg, Germany.|Physiology Department, Faculty of Medicine and Health Sciences, An-Najah Natinal University, Nablus, Palestine.
authors.forename: Belal
authors.initials: B
authors.lastname: Rahhal
authors.affiliation: Institute for Anatomy and Cell Biology, Department of Molecular Embryology, Albert-Ludwigs-University Freiburg, Albertstrasse 17, 79104, Freiburg, Germany.
authors.forename: Björn
authors.initials: B
authors.lastname: Spittau
authors.affiliation: Institute for Anatomy and Cell Biology, Department of Molecular Embryology, Albert-Ludwigs-University Freiburg, Albertstrasse 17, 79104, Freiburg, Germany. eleni.roussa@anat.uni-freiburg.de.|Institute for Anatomy and Cell Biology, Department of Neuroanatomy, Albert-Ludwigs-University Freiburg, Freiburg, Germany. eleni.roussa@anat.uni-freiburg.de.
authors.forename: Eleni
authors.initials: E
authors.lastname: Roussa
mesh_terms: D016229:Amyloid beta-Peptides / Q000378:metabolism; D000818:Animals; D000831:Animals, Newborn; D015816:Cell Adhesion Molecules, Neuronal / Q000378:metabolism*; D004622:Embryo, Mammalian / Q000378:metabolism; D016326:Extracellular Matrix Proteins / Q000378:metabolism*; D026502:LDL-Receptor Related Proteins / Q000378:metabolism; D008636:Mesencephalon / Q000166:cytology / Q000378:metabolism*; D051379:Mice; D017072:Neostriatum / Q000166:cytology / Q000378:metabolism*; D009419:Nerve Tissue Proteins / Q000378:metabolism*; D021381:Protein Transport; D011973:Receptors, LDL / Q000378:metabolism; D000091042:Reelin Protein; D012697:Serine Endopeptidases / Q000378:metabolism*; D015398:Signal Transduction
chemical_list: D016229:Amyloid beta-Peptides; D015816:Cell Adhesion Molecules, Neuronal; C103773:Dab1 protein, mouse; D016326:Extracellular Matrix Proteins; D026502:LDL-Receptor Related Proteins; D009419:Nerve Tissue Proteins; D011973:Receptors, LDL; D000091042:Reelin Protein; C036053:VLDL receptor; C098773:low density lipoprotein receptor-related protein 8; C000717128:Reln protein, mouse; D012697:Serine Endopeptidases