title: Post-natal development of the Reeler mouse cerebellum: An ultrastructural study.
abstract: Reelin, an extracellular protein promoting neuronal migration in brain areas with a laminar architecture, is missing in the Reeler mouse (reelin(-/-)). Several studies indicate that the protein is also necessary for correct dendritic outgrowth and synapse formation in the adult forebrain. By transmission electron microscopy, we characterize the development and synaptic organization of the cerebellar cortex in Reeler mice and wild type control littermates at birth, postnatal day (P) 5, 7, 10 and 15. Ultrastructural analysis shows deep alterations in cortical architecture and mispositioning of the Purkinje neurons (Pns), which remain deeply embedded in a central cellular mass within the white matter, with highly immature features. Quantitative examination shows that Reeler mice display: (i) a lower density of granule cells and a higher density of Pns, from P10; (ii) a lower density of synaptic contacts between Pn dendrites and parallel or climbing fibers, from P5; (iii) a lower density of synaptic contacts between basket cells and Pns, from P5; and (iv) a lower density of mossy fiber rosettes, from P10. Our results demonstrate that Reelin profoundly affects the structure and synaptic connectivity of post-natal mouse cerebellum.
authors.affiliation: University of Turin, Department of Veterinary Sciences, Italy. Electronic address: claudia.castagna@unito.it.
authors.forename: Claudia
authors.initials: C
authors.lastname: Castagna
authors.affiliation: University of Turin, Department of Veterinary Sciences, Italy.
authors.forename: Patrizia
authors.initials: P
authors.lastname: Aimar
authors.affiliation: University of Turin, Department of Veterinary Sciences, Italy.
authors.forename: Silvia
authors.initials: S
authors.lastname: Alasia
authors.affiliation: INN - Istituto Nazionale di Neuroscienze, Italy.
authors.forename: Laura
authors.initials: L
authors.lastname: Lossi
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D015816:Cell Adhesion Molecules, Neuronal / Q000235:genetics / Q000502:physiology; D002525:Cerebellar Cortex / Q000254:growth & development / Q000648:ultrastructure; D002531:Cerebellum / Q000254:growth & development* / Q000648:ultrastructure*; D016326:Extracellular Matrix Proteins / Q000235:genetics / Q000502:physiology; D051379:Mice; D008818:Mice, Neurologic Mutants / Q000254:growth & development*; D009412:Nerve Fibers / Q000502:physiology / Q000648:ultrastructure; D009419:Nerve Tissue Proteins / Q000235:genetics / Q000502:physiology; D011689:Purkinje Cells / Q000502:physiology / Q000648:ultrastructure; D000091042:Reelin Protein; D012697:Serine Endopeptidases / Q000235:genetics / Q000502:physiology; D013569:Synapses / Q000502:physiology / Q000648:ultrastructure
chemical_list: D015816:Cell Adhesion Molecules, Neuronal; D016326:Extracellular Matrix Proteins; D009419:Nerve Tissue Proteins; D000091042:Reelin Protein; C000717128:Reln protein, mouse; D012697:Serine Endopeptidases
keywords: Cerebellum; Development; Mouse; Purkinje neurons; Reeler; Synapse; Ultrastructure