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Merighi A, Lossi L. Co-cultures of cerebellar slices from mice with different reelin genetic backgrounds as a model to study cortical lamination. F1000Res 2023; 11:1183. [PMID: 37881513 PMCID: PMC10594056 DOI: 10.12688/f1000research.126787.1] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 09/07/2023] [Indexed: 10/27/2023] Open
Abstract
Background: Reelin has fundamental functions in the developing and mature brain. Its absence gives rise to the Reeler phenotype in mice, the first described cerebellar mutation. In homozygous mutants missing the Reelin gene ( reln -/-), neurons are incapable of correctly positioning themselves in layered brain areas such as the cerebral and cerebellar cortices. We here demonstrate that by employing ex vivo cultured cerebellar slices one can reduce the number of animals and use a non-recovery procedure to analyze the effects of Reelin on the migration of Purkinje neurons (PNs). Methods: We generated mouse hybrids (L7-GFP relnF1/) with green fluorescent protein (GFP)-tagged PNs, directly visible under fluorescence microscopy. We then cultured the slices obtained from mice with different reln genotypes and demonstrated that when the slices from reln -/- mutants were co-cultured with those from reln +/- mice, the Reelin produced by the latter induced migration of the PNs to partially rescue the normal layered cortical histology. We have confirmed this observation with Voronoi tessellation to analyze PN dispersion. Results: In images of the co-cultured slices from reln -/- mice, Voronoi polygons were larger than in single-cultured slices of the same genetic background but smaller than those generated from slices of reln +/- animals. The mean roundness factor, area disorder, and roundness factor homogeneity were different when slices from reln -/- mice were cultivated singularly or co-cultivated, supporting mathematically the transition from the clustered organization of the PNs in the absence of Reelin to a layered structure when the protein is supplied ex vivo. Conclusions: Neurobiologists are the primary target users of this 3Rs approach. They should adopt it for the possibility to study and manipulate ex vivo the activity of a brain-secreted or genetically engineered protein (scientific perspective), the potential reduction (up to 20%) of the animals used, and the total avoidance of severe surgery (3Rs perspective).
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Affiliation(s)
- Adalberto Merighi
- Department of Veterinary Sciences, University of Turin, Grugliasco, 10095, Italy
| | - Laura Lossi
- Department of Veterinary Sciences, University of Turin, Grugliasco, 10095, Italy
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2
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Merighi A, Lossi L. Co-cultures of cerebellar slices from mice with different reelin genetic backgrounds as a model to study cortical lamination. F1000Res 2023; 11:1183. [PMID: 37881513 PMCID: PMC10594056 DOI: 10.12688/f1000research.126787.2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 09/07/2023] [Indexed: 10/27/2023] Open
Abstract
Background: Reelin has fundamental functions in the developing and mature brain. Its absence gives rise to the Reeler phenotype in mice, the first described cerebellar mutation. In homozygous mutants missing the Reelin gene ( reln -/-), neurons are incapable of correctly positioning themselves in layered brain areas such as the cerebral and cerebellar cortices. We here demonstrate that by employing ex vivo cultured cerebellar slices one can reduce the number of animals and use a non-recovery procedure to analyze the effects of Reelin on the migration of Purkinje neurons (PNs). Methods: We generated mouse hybrids (L7-GFP relnF1/) with green fluorescent protein (GFP)-tagged PNs, directly visible under fluorescence microscopy. We then cultured the slices obtained from mice with different reln genotypes and demonstrated that when the slices from reln -/- mutants were co-cultured with those from reln +/- mice, the Reelin produced by the latter induced migration of the PNs to partially rescue the normal layered cortical histology. We have confirmed this observation with Voronoi tessellation to analyze PN dispersion. Results: In images of the co-cultured slices from reln -/- mice, Voronoi polygons were larger than in single-cultured slices of the same genetic background but smaller than those generated from slices of reln +/- animals. The mean roundness factor, area disorder, and roundness factor homogeneity were different when slices from reln -/- mice were cultivated singularly or co-cultivated, supporting mathematically the transition from the clustered organization of the PNs in the absence of Reelin to a layered structure when the protein is supplied ex vivo. Conclusions: Neurobiologists are the primary target users of this 3Rs approach. They should adopt it for the possibility to study and manipulate ex vivo the activity of a brain-secreted or genetically engineered protein (scientific perspective), the potential reduction (up to 20%) of the animals used, and the total avoidance of severe surgery (3Rs perspective).
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Affiliation(s)
- Adalberto Merighi
- Department of Veterinary Sciences, University of Turin, Grugliasco, 10095, Italy
| | - Laura Lossi
- Department of Veterinary Sciences, University of Turin, Grugliasco, 10095, Italy
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The Reeler Mouse: A Translational Model of Human Neurological Conditions, or Simply a Good Tool for Better Understanding Neurodevelopment? J Clin Med 2019; 8:jcm8122088. [PMID: 31805691 PMCID: PMC6947477 DOI: 10.3390/jcm8122088] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2019] [Revised: 11/26/2019] [Accepted: 11/28/2019] [Indexed: 12/25/2022] Open
Abstract
The first description of the Reeler mutation in mouse dates to more than fifty years ago, and later, its causative gene (reln) was discovered in mouse, and its human orthologue (RELN) was demonstrated to be causative of lissencephaly 2 (LIS2) and about 20% of the cases of autosomal-dominant lateral temporal epilepsy (ADLTE). In both human and mice, the gene encodes for a glycoprotein referred to as reelin (Reln) that plays a primary function in neuronal migration during development and synaptic stabilization in adulthood. Besides LIS2 and ADLTE, RELN and/or other genes coding for the proteins of the Reln intracellular cascade have been associated substantially to other conditions such as spinocerebellar ataxia type 7 and 37, VLDLR-associated cerebellar hypoplasia, PAFAH1B1-associated lissencephaly, autism, and schizophrenia. According to their modalities of inheritances and with significant differences among each other, these neuropsychiatric disorders can be modeled in the homozygous (reln−/−) or heterozygous (reln+/−) Reeler mouse. The worth of these mice as translational models is discussed, with focus on their construct and face validity. Description of face validity, i.e., the resemblance of phenotypes between the two species, centers onto the histological, neurochemical, and functional observations in the cerebral cortex, hippocampus, and cerebellum of Reeler mice and their human counterparts.
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Castagna C, Merighi A, Lossi L. Decreased Expression of Synaptophysin 1 (SYP1 Major Synaptic Vesicle Protein p38) and Contactin 6 (CNTN6/NB3) in the Cerebellar Vermis of reln Haplodeficient Mice. Cell Mol Neurobiol 2019; 39:833-856. [PMID: 31098770 DOI: 10.1007/s10571-019-00683-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2018] [Accepted: 05/02/2019] [Indexed: 01/17/2023]
Abstract
Reeler heterozygous mice (reln+/-) are seemingly normal but haplodeficient in reln, a gene implicated in autism. Structural/neurochemical alterations in the reln+/- brain are subtle and difficult to demonstrate. Therefore, the usefulness of these mice in translational research is still debated. As evidence implicated several synapse-related genes in autism and the cerebellar vermis is structurally altered in the condition, we have investigated the expression of synaptophysin 1 (SYP1) and contactin 6 (CNTN6) within the vermis of reln+/- mice. Semi-thin plastic sections of the vermis from adult mice of both sexes and different genotypes (reln+/- and reln+/+) were processed with an indirect immunofluorescence protocol. Immunofluorescence was quantified on binary images and statistically analyzed. Reln+/- males displayed a statistically significant reduction of 11.89% in the expression of SYP1 compared to sex-matched wild-type animals, whereas no differences were observed between reln+/+ and reln+/- females. In reln+/- male mice, reductions were particularly evident in the molecular layer: 10.23% less SYP1 than reln+/+ males and 5.84% < reln+/+ females. In reln+/- females, decrease was 9.84% versus reln+/+ males and 5.43% versus reln+/+ females. Both reln+/- males and females showed a stronger decrease in CNTN6 expression throughout all the three cortical layers of the vermis: 17-23% in the granular layer, 24-26% in the Purkinje cell layer, and 9-14% in the molecular layer. Altogether, decrease of vermian SYP1 and CNTN6 in reln+/- mice displayed patterns compatible with the structural modifications of the autistic cerebellum. Therefore, these mice may be a good model in translational studies.
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Affiliation(s)
- Claudia Castagna
- Department of Veterinary Sciences, University of Turin, Largo Paolo Braccini 2, I-10095, Turin, Grugliasco (TO), Italy.
| | - Adalberto Merighi
- Department of Veterinary Sciences, University of Turin, Largo Paolo Braccini 2, I-10095, Turin, Grugliasco (TO), Italy
| | - Laura Lossi
- Department of Veterinary Sciences, University of Turin, Largo Paolo Braccini 2, I-10095, Turin, Grugliasco (TO), Italy
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Habicht JL, Kiessling C, Winkelmann A. Bodies for Anatomy Education in Medical Schools: An Overview of the Sources of Cadavers Worldwide. ACADEMIC MEDICINE : JOURNAL OF THE ASSOCIATION OF AMERICAN MEDICAL COLLEGES 2018; 93:1293-1300. [PMID: 29561275 PMCID: PMC6112846 DOI: 10.1097/acm.0000000000002227] [Citation(s) in RCA: 120] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
The International Federation of Associations of Anatomists (IFAA) recommended in 2012 that only donated bodies be used for anatomy teaching and research. However, in many countries around the world, anatomists still depend on bodies that do not stem from voluntary donations by the deceased but, rather, are "unclaimed." A broad search of the literature was conducted to produce a baseline overview of the sources of cadavers used for anatomy teaching in undergraduate medical curricula on a global scale. Information from the literature search was supplemented with data from a 2016-2017 survey of selected senior local anatomists. Of 165 countries with medical schools, information was gathered for 71. In 22 (32%) of the 68 countries that use cadavers for anatomy teaching, body donation is the exclusive source of bodies. However, in most other countries, unclaimed bodies remain the main (n = 18; 26%) or exclusive (n = 21; 31%) source. Some countries import cadavers from abroad, mainly from the United States or India. In one country, bodies of executed persons are given to anatomy departments. The heterogeneous geographical distribution of body sources cannot easily be accounted for, but religion, culture, and folk beliefs about what should happen to bodies after death seem to play a role. Implementation of the IFAA recommendations still has a long way to go, but it is encouraging that functioning body donation programs exist on all continents and that there are examples of recent rises in donations and of anatomists initiating new donation programs.
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Affiliation(s)
- Juri L. Habicht
- J.L. Habicht is a third-year medical student, Medical School Brandenburg, Brandenburg Campus, Brandenburg an der Havel, Germany
| | - Claudia Kiessling
- C. Kiessling is head of the assessment department, Medical School Brandenburg, Neuruppin Campus, Neuruppin, Germany; ORCID: http://orcid.org/0000-0003-4104-4854
| | - Andreas Winkelmann
- A. Winkelmann is full professor, Institute of Anatomy, Medical School Brandenburg, Neuruppin Campus, Neuruppin, Germany, and chair, Federative International Committee for Ethics and Medical Humanities, International Federation of Associations of Anatomists (IFAA); ORCID: http://orcid.org/0000-0003-1047-2477
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Shehabeldin R, Lutz D, Karsak M, Frotscher M, Krieglstein K, Sharaf A. Reelin controls the positioning of brainstem serotonergic raphe neurons. PLoS One 2018; 13:e0200268. [PMID: 30001399 PMCID: PMC6042745 DOI: 10.1371/journal.pone.0200268] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2017] [Accepted: 06/23/2018] [Indexed: 11/20/2022] Open
Abstract
Serotonin (5-HT) acts as both a morphogenetic factor during early embryonic development and a neuromodulator of circuit plasticity in the mature brain. Dysregulation of serotonin signaling during critical periods is involved in developmental neurological disorders, such as schizophrenia and autism. In this study we focused on the consequences of defect reelin signaling for the development of the brainstem serotonergic raphe system. We observed that reelin signaling components are expressed by serotonergic neurons during the critical period of their lateral migration. Further, we found that reelin signaling is important for the normal migration of rostral, but not caudal hindbrain raphe nuclei and that reelin deficiency results in the malformation of the paramedian raphe nucleus and the lateral wings of the dorsal raphe nuclei. Additionally, we showed that serotonergic neurons projections to laminated brain structures were severely altered. With this study, we propose that the perturbation of canonical reelin signaling interferes with the orientation of tangentially, but not radially, migrating brainstem 5-HT neurons. Our results open the window for further studies on the interaction of reelin and serotonin and the pathogenesis of neurodevelopmental disorders.
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Affiliation(s)
- Reham Shehabeldin
- Institute of Anatomy and Cell Biology, Department of Molecular Embryology, Albert-Ludwigs-Universität, Freiburg, Germany
| | - David Lutz
- Institute for Structural Neurobiology, Center for Molecular Neurobiology Hamburg (ZMNH), University Medical Center Hamburg-Eppendorf (UKE), Hamburg, Germany
| | - Meliha Karsak
- Research Group Neuronal and Cellular Signal Transduction, ZMNH, University Medical Center Hamburg-Eppendorf (UKE), Hamburg, Germany
| | - Michael Frotscher
- Institute for Structural Neurobiology, Center for Molecular Neurobiology Hamburg (ZMNH), University Medical Center Hamburg-Eppendorf (UKE), Hamburg, Germany
| | - Kerstin Krieglstein
- Institute of Anatomy and Cell Biology, Department of Molecular Embryology, Albert-Ludwigs-Universität, Freiburg, Germany
| | - Ahmed Sharaf
- Institute of Anatomy and Cell Biology, Department of Molecular Embryology, Albert-Ludwigs-Universität, Freiburg, Germany
- Institute for Structural Neurobiology, Center for Molecular Neurobiology Hamburg (ZMNH), University Medical Center Hamburg-Eppendorf (UKE), Hamburg, Germany
- Research Group Neuronal and Cellular Signal Transduction, ZMNH, University Medical Center Hamburg-Eppendorf (UKE), Hamburg, Germany
- Department of Histology and Cytology, Faculty of Veterinary Medicine, Zagazig University, Zagazig, Egypt
- * E-mail:
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Whittaker DE, Riegman KL, Kasah S, Mohan C, Yu T, Sala BP, Hebaishi H, Caruso A, Marques AC, Michetti C, Smachetti MES, Shah A, Sabbioni M, Kulhanci O, Tee WW, Reinberg D, Scattoni ML, Volk H, McGonnell I, Wardle FC, Fernandes C, Basson MA. The chromatin remodeling factor CHD7 controls cerebellar development by regulating reelin expression. J Clin Invest 2017; 127:874-887. [PMID: 28165338 PMCID: PMC5330721 DOI: 10.1172/jci83408] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2015] [Accepted: 12/12/2016] [Indexed: 12/21/2022] Open
Abstract
The mechanisms underlying the neurodevelopmental deficits associated with CHARGE syndrome, which include cerebellar hypoplasia, developmental delay, coordination problems, and autistic features, have not been identified. CHARGE syndrome has been associated with mutations in the gene encoding the ATP-dependent chromatin remodeler CHD7. CHD7 is expressed in neural stem and progenitor cells, but its role in neurogenesis during brain development remains unknown. Here we have shown that deletion of Chd7 from cerebellar granule cell progenitors (GCps) results in reduced GCp proliferation, cerebellar hypoplasia, developmental delay, and motor deficits in mice. Genome-wide expression profiling revealed downregulated expression of the gene encoding the glycoprotein reelin (Reln) in Chd7-deficient GCps. Recessive RELN mutations have been associated with severe cerebellar hypoplasia in humans. We found molecular and genetic evidence that reductions in Reln expression contribute to GCp proliferative defects and cerebellar hypoplasia in GCp-specific Chd7 mouse mutants. Finally, we showed that CHD7 is necessary for maintaining an open, accessible chromatin state at the Reln locus. Taken together, this study shows that Reln gene expression is regulated by chromatin remodeling, identifies CHD7 as a previously unrecognized upstream regulator of Reln, and provides direct in vivo evidence that a mammalian CHD protein can control brain development by modulating chromatin accessibility in neuronal progenitors.
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Affiliation(s)
- Danielle E. Whittaker
- King’s College London, Department of Craniofacial Development and Stem Cell Biology, Guy’s Hospital Tower Wing
- Department of Comparative Biomedical Sciences, Royal Veterinary College, and
| | - Kimberley L.H. Riegman
- King’s College London, Department of Craniofacial Development and Stem Cell Biology, Guy’s Hospital Tower Wing
| | - Sahrunizam Kasah
- King’s College London, Department of Craniofacial Development and Stem Cell Biology, Guy’s Hospital Tower Wing
| | - Conor Mohan
- King’s College London, Department of Craniofacial Development and Stem Cell Biology, Guy’s Hospital Tower Wing
| | - Tian Yu
- King’s College London, Department of Craniofacial Development and Stem Cell Biology, Guy’s Hospital Tower Wing
| | - Blanca Pijuan Sala
- King’s College London, Department of Craniofacial Development and Stem Cell Biology, Guy’s Hospital Tower Wing
| | - Husam Hebaishi
- King’s College London, Randall Division, New Hunt’s House, London, United Kingdom
| | - Angela Caruso
- Neurotoxicology and Neuroendocrinology Section, Department of Cell Biology and Neuroscience, Istituto Superiore di Sanità, and
- School of Behavioural Neuroscience, Department of Psychology, Sapienza University of Rome, Rome, Italy
| | - Ana Claudia Marques
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, United Kingdom
| | - Caterina Michetti
- Neurotoxicology and Neuroendocrinology Section, Department of Cell Biology and Neuroscience, Istituto Superiore di Sanità, and
- Department of Physiology and Pharmacology “V. Erspamer,” Sapienza University of Rome, Rome, Italy
| | | | - Apar Shah
- King’s College London, Department of Craniofacial Development and Stem Cell Biology, Guy’s Hospital Tower Wing
| | - Mara Sabbioni
- Neurotoxicology and Neuroendocrinology Section, Department of Cell Biology and Neuroscience, Istituto Superiore di Sanità, and
| | - Omer Kulhanci
- MRC Social, Genetic & Developmental Psychiatry Centre, Institute of Psychiatry, Psychology & Neuroscience, King’s College London, London, United Kingdom
| | - Wee-Wei Tee
- Howard Hughes Medical Institute, Department of Molecular Pharmacology and Biochemistry, New York University School of Medicine, New York, New York, USA
| | - Danny Reinberg
- Howard Hughes Medical Institute, Department of Molecular Pharmacology and Biochemistry, New York University School of Medicine, New York, New York, USA
| | - Maria Luisa Scattoni
- Neurotoxicology and Neuroendocrinology Section, Department of Cell Biology and Neuroscience, Istituto Superiore di Sanità, and
| | - Holger Volk
- Department of Comparative Biomedical Sciences, Royal Veterinary College, and
| | - Imelda McGonnell
- Department of Comparative Biomedical Sciences, Royal Veterinary College, and
| | - Fiona C. Wardle
- King’s College London, Randall Division, New Hunt’s House, London, United Kingdom
| | - Cathy Fernandes
- MRC Social, Genetic & Developmental Psychiatry Centre, Institute of Psychiatry, Psychology & Neuroscience, King’s College London, London, United Kingdom
- King’s College London, MRC Centre for Neurodevelopmental Disorders, New Hunt’s House, London, United Kingdom
| | - M. Albert Basson
- King’s College London, Department of Craniofacial Development and Stem Cell Biology, Guy’s Hospital Tower Wing
- King’s College London, MRC Centre for Neurodevelopmental Disorders, New Hunt’s House, London, United Kingdom
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Herrfurth L, Theis V, Matschke V, May C, Marcus K, Theiss C. Morphological Plasticity of Emerging Purkinje Cells in Response to Exogenous VEGF. Front Mol Neurosci 2017; 10:2. [PMID: 28194096 PMCID: PMC5276996 DOI: 10.3389/fnmol.2017.00002] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2016] [Accepted: 01/04/2017] [Indexed: 12/12/2022] Open
Abstract
Vascular endothelial growth factor (VEGF) is well known as the growth factor with wide-ranging functions even in the central nervous system (CNS). Presently, most attention is given to the investigation of its role in neuronal protection, growth and maturation processes, whereby most effects are mediated through VEGF receptor 2 (VEGFR-2). The purpose of our current study is to provide new insights into the impact of VEGF on immature and mature Purkinje cells (PCs) in accordance with maturity and related receptor expression. Therefore, to expand our knowledge of VEGF effects in PCs development and associated VEGFR-2 expression, we used cultivated organotypic cerebellar slice cultures in immunohistochemical or microinjection studies, followed by confocal laser scanning microscopy (CLSM) and morphometric analysis. Additionally, we incorporated in our study the method of laser microdissection, followed by quantitative polymerase chain reaction (qPCR). For the first time we could show the age-dependent VEGF sensitivity of PCs with the largest promoting effects being on dendritic length and cell soma size in neonatal and juvenile stages. Once mature, PCs were no longer susceptible to VEGF stimulation. Analysis of VEGFR-2 expression revealed its presence in PCs throughout development, which underlined its mediating functions in neuronal cells.
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Affiliation(s)
- Leonard Herrfurth
- Medizinische Fakultät, Institut für Anatomie, Abteilung für Cytologie, Ruhr-Universität Bochum Bochum, Germany
| | - Verena Theis
- Medizinische Fakultät, Institut für Anatomie, Abteilung für Cytologie, Ruhr-Universität Bochum Bochum, Germany
| | - Veronika Matschke
- Medizinische Fakultät, Institut für Anatomie, Abteilung für Cytologie, Ruhr-Universität Bochum Bochum, Germany
| | - Caroline May
- Abteilung für Medizinische Proteomik/Bioanalytik, Medizinisches Proteom-Center, Ruhr-University Bochum Bochum, Germany
| | - Katrin Marcus
- Abteilung für Medizinische Proteomik/Bioanalytik, Medizinisches Proteom-Center, Ruhr-University Bochum Bochum, Germany
| | - Carsten Theiss
- Medizinische Fakultät, Institut für Anatomie, Abteilung für Cytologie, Ruhr-Universität Bochum Bochum, Germany
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Cocito C, Merighi A, Giacobini M, Lossi L. Alterations of Cell Proliferation and Apoptosis in the Hypoplastic Reeler Cerebellum. Front Cell Neurosci 2016; 10:141. [PMID: 27252624 PMCID: PMC4879145 DOI: 10.3389/fncel.2016.00141] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2016] [Accepted: 05/10/2016] [Indexed: 12/24/2022] Open
Abstract
A mutation of the reln gene gives rise to the Reeler mouse (reln−∕−) displaying an ataxic phenotype and cerebellar hypoplasia. We have characterized the neurochemistry of postnatal (P0–P60) reln−∕− mouse cerebella with specific attention to the intervention of cell proliferation and apoptosis in the P0–P25 interval. Homozygous reln−∕− mice and age-matched controls were analyzed by immunofluorescence using primary antibodies against NeuN, calbindin, GFAP, vimentin, SMI32, and GAD67. Proliferation and apoptosis were detected after a single intraperitoneal BrdU injection and by the TUNEL assay with anti-digoxigenin rhodamine-conjugated antibodies. Quantitative analysis with descriptive and predictive statistics was used to calculate cell densities (number/mm2) after fluorescent nuclear stain (TCD, total cell density), labeling with BrdU (PrCD, proliferating cell density), or TUNEL (ApoCD, apoptotic cell density). By this approach we first have shown that the temporal pattern of expression of neuronal/glial markers in postnatal cerebellum is not affected by the Reeler mutation. Then, we have demonstrated that the hypoplasia in the Reeler mouse cerebellum is consequent to reduction of cortical size and cellularity (TCD), and that TCD is, in turn, linked to quantitative differences in the extent of cell proliferation and apoptosis, as well as derangements in their temporal trends during postnatal maturation. Finally, we have calculated that PrCD is the most important predictive factor to determine TCD in the cerebellar cortex of the mutants. These results support the notion that, beside the well-known consequences onto the migration of the cerebellar neurons, the lack of Reelin results in a measurable deficit in neural proliferation.
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Affiliation(s)
- Carolina Cocito
- Laboratory of Neuroscience, Department of Veterinary Sciences, University of Turin Grugliasco, Italy
| | - Adalberto Merighi
- Laboratory of Neuroscience, Department of Veterinary Sciences, University of Turin Grugliasco, Italy
| | - Mario Giacobini
- Laboratory of Dynamical Systems and Epidemiology, Department of Veterinary Sciences, University of Turin Grugliasco, Italy
| | - Laura Lossi
- Laboratory of Neuroscience, Department of Veterinary Sciences, University of Turin Grugliasco, Italy
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Magliaro C, Cocito C, Bagatella S, Merighi A, Ahluwalia A, Lossi L. The number of Purkinje neurons and their topology in the cerebellar vermis of normal and reln haplodeficient mouse. Ann Anat 2016; 207:68-75. [PMID: 26996540 DOI: 10.1016/j.aanat.2016.02.009] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2015] [Revised: 02/02/2016] [Accepted: 02/25/2016] [Indexed: 12/14/2022]
Abstract
The Reeler heterozygous mice (reln(+/-)) are haplodeficient in the gene (reln) encoding for the reelin glycoprotein (RELN) and display reductions in brain/peripheral RELN similar to autistic or schizophrenic patients. Cytoarchitectonic alterations of the reln(+/-) brain may be subtle, and are difficult to demonstrate by current histological approaches. We analyzed the number and topological organization of the Purkinje neurons (PNs) in five vermal lobules - central (II-III), culmen (IV-V), tuber (VIIb), uvula (IX), and nodulus (X) - that process different types of afferent functional inputs in reln(+/+) and reln(+/-) adult mice (P60) of both sexes (n=24). Animals were crossed with L7GFP mice so that the GFP-tagged PNs could be directly identified in cryosections. Digital images from these sections were processed with different open source software for quantitative topological and statistical analyses. Diversity indices calculated were: maximum caliper, density, area of soma, dispersion along the XZ axis, and dispersion along the YZ axis. We demonstrate: i. reduction in density of PNs in reln(+/-) males (14.37%) and reln(+/-) females (17.73%) compared to reln(+/+) males; ii. that reln(+/-) males have larger PNs than other genotypes, and females (irrespective of the reln genetic background) have smaller PNs than reln(+/+) males; iii. PNs are more chaotically arranged along the YZ axis in reln(+/-) males than in reln(+/+) males and, except in central lobulus, reln(+/-) females. Therefore, image processing and statistics reveal previously unforeseen gender and genotype-related structural differences in cerebellum that may be clues for the definition of novel biomarkers in human psychiatric disorders.
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Affiliation(s)
- Chiara Magliaro
- University of Pisa, Research Center E. Piaggio, Faculty of Engineering, Pisa, Italy
| | - Carolina Cocito
- University of Turin, Department of Veterinary Sciences, Turin, Italy
| | - Stefano Bagatella
- University of Turin, Department of Veterinary Sciences, Turin, Italy
| | - Adalberto Merighi
- University of Turin, Department of Veterinary Sciences, Turin, Italy
| | - Arti Ahluwalia
- University of Pisa, Research Center E. Piaggio, Faculty of Engineering, Pisa, Italy
| | - Laura Lossi
- University of Turin, Department of Veterinary Sciences, Turin, Italy.
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11
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Lossi L, D’Angelo L, De Girolamo P, Merighi A. Anatomical features for an adequate choice of experimental animal model in biomedicine: II. Small laboratory rodents, rabbit, and pig. Ann Anat 2016; 204:11-28. [DOI: 10.1016/j.aanat.2015.10.002] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2015] [Revised: 10/01/2015] [Accepted: 10/05/2015] [Indexed: 01/24/2023]
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Cell death and neurodegeneration in the postnatal development of cerebellar vermis in normal and Reeler mice. Ann Anat 2016; 207:76-90. [PMID: 26931496 DOI: 10.1016/j.aanat.2016.01.010] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2015] [Accepted: 01/25/2016] [Indexed: 12/18/2022]
Abstract
Programmed cell death (PCD) was demonstrated in neurons and glia in normal brain development, plasticity, and aging, but also in neurodegeneration. (Macro)autophagy, characterized by cytoplasmic vacuolization and activation of lysosomal hydrolases, and apoptosis, typically entailing cell shrinkage, chromatin and nuclear condensation, are the two more common forms of PCD. Their underlying intracellular pathways are partly shared and neurons can die following both modalities, according to the type of death-triggering stimulus. Reelin is an extracellular protein necessary for proper neuronal migration and brain lamination. In the mutant Reeler mouse, its absence causes neuronal mispositioning, with a notable degree of cerebellar hypoplasia that was tentatively related to an increase in PCD. We have carried out an ultrastructural analysis on the occurrence and type of postnatal PCD affecting the cerebellar neurons in normal and Reeler mice. In the forming cerebellar cortex, PCD took the form of apoptosis or autophagy and mainly affected the cerebellar granule cells (CGCs). Densities of apoptotic CGCs were comparable in both mouse strains at P0-P10, while, in mutants, they increased to become significantly higher at P15. In WT mice the density of autophagic neurons did not display statistically significant differences in the time interval examined in this study, whereas it was reduced in Reeler in the P0-P10 interval, but increased at P15. Besides CGCs, the Purkinje neurons also displayed autophagic features in both WT and Reeler mice. Therefore, cerebellar neurons undergo different types of PCD and a Reelin deficiency affects the type and degree of neuronal death during postnatal development of the cerebellum.
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Silvestri L, Paciscopi M, Soda P, Biamonte F, Iannello G, Frasconi P, Pavone FS. Quantitative neuroanatomy of all Purkinje cells with light sheet microscopy and high-throughput image analysis. Front Neuroanat 2015; 9:68. [PMID: 26074783 PMCID: PMC4445386 DOI: 10.3389/fnana.2015.00068] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2015] [Accepted: 05/11/2015] [Indexed: 02/02/2023] Open
Abstract
Characterizing the cytoarchitecture of mammalian central nervous system on a brain-wide scale is becoming a compelling need in neuroscience. For example, realistic modeling of brain activity requires the definition of quantitative features of large neuronal populations in the whole brain. Quantitative anatomical maps will also be crucial to classify the cytoarchtitectonic abnormalities associated with neuronal pathologies in a high reproducible and reliable manner. In this paper, we apply recent advances in optical microscopy and image analysis to characterize the spatial distribution of Purkinje cells (PCs) across the whole cerebellum. Light sheet microscopy was used to image with micron-scale resolution a fixed and cleared cerebellum of an L7-GFP transgenic mouse, in which all PCs are fluorescently labeled. A fast and scalable algorithm for fully automated cell identification was applied on the image to extract the position of all the fluorescent PCs. This vectorized representation of the cell population allows a thorough characterization of the complex three-dimensional distribution of the neurons, highlighting the presence of gaps inside the lamellar organization of PCs, whose density is believed to play a significant role in autism spectrum disorders. Furthermore, clustering analysis of the localized somata permits dividing the whole cerebellum in groups of PCs with high spatial correlation, suggesting new possibilities of anatomical partition. The quantitative approach presented here can be extended to study the distribution of different types of cell in many brain regions and across the whole encephalon, providing a robust base for building realistic computational models of the brain, and for unbiased morphological tissue screening in presence of pathologies and/or drug treatments.
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Affiliation(s)
- Ludovico Silvestri
- National Institute of Optics, National Research Council Sesto Fiorentino, Italy ; European Laboratory for Non-Linear Spectroscopy Sesto Fiorentino, Italy
| | - Marco Paciscopi
- Department of Information Engineering, University of Florence Florence, Italy
| | - Paolo Soda
- Department of Engineering, University Campus Bio-Medico of Rome Rome, Italy
| | - Filippo Biamonte
- Institute of Histology and Embryology, Catholic University of the Sacred Heart "A. Gemelli", Rome Italy
| | - Giulio Iannello
- Department of Engineering, University Campus Bio-Medico of Rome Rome, Italy
| | - Paolo Frasconi
- European Laboratory for Non-Linear Spectroscopy Sesto Fiorentino, Italy
| | - Francesco S Pavone
- National Institute of Optics, National Research Council Sesto Fiorentino, Italy ; European Laboratory for Non-Linear Spectroscopy Sesto Fiorentino, Italy ; Department of Physics and Astronomy, University of Florence Sesto Fiorentino, Italy ; International Center for Computational Neurophotonics Sesto Fiorentino, Italy
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Cendelin J. From mice to men: lessons from mutant ataxic mice. CEREBELLUM & ATAXIAS 2014; 1:4. [PMID: 26331028 PMCID: PMC4549131 DOI: 10.1186/2053-8871-1-4] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 02/28/2014] [Accepted: 04/21/2014] [Indexed: 01/01/2023]
Abstract
Ataxic mutant mice can be used to represent models of cerebellar degenerative disorders. They serve for investigation of cerebellar function, pathogenesis of degenerative processes as well as of therapeutic approaches. Lurcher, Hot-foot, Purkinje cell degeneration, Nervous, Staggerer, Weaver, Reeler, and Scrambler mouse models and mouse models of SCA1, SCA2, SCA3, SCA6, SCA7, SCA23, DRPLA, Niemann-Pick disease and Friedreich ataxia are reviewed with special regard to cerebellar pathology, pathogenesis, functional changes and possible therapeutic influences, if any. Finally, benefits and limitations of mouse models are discussed.
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Affiliation(s)
- Jan Cendelin
- Department of Pathophysiology, Faculty of Medicine in Pilsen, Charles University in Prague, Lidicka 1, 301 66 Plzen, Czech Republic ; Biomedical Centre, Faculty of Medicine in Pilsen, Charles University in Prague, Plzen, Czech Republic
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