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Neurospheres obtained from the ciliary margin of the chicken eye possess positional values and retinal ganglion cells differentiated from them respond to EphA/ephrin-A system. Exp Eye Res 2022; 217:108965. [DOI: 10.1016/j.exer.2022.108965] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2021] [Revised: 12/14/2021] [Accepted: 01/25/2022] [Indexed: 11/23/2022]
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Medori M, Spelzini G, Scicolone G. Molecular complexity of visual mapping: a challenge for regenerating therapy. Neural Regen Res 2020; 15:382-389. [PMID: 31571645 PMCID: PMC6921353 DOI: 10.4103/1673-5374.266044] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Investigating the cellular and molecular mechanisms involved in the development of topographically ordered connections in the central nervous system constitutes an important issue in neurobiology because these connections are the base of the central nervous system normal function. The dominant model to study the development of topographic maps is the projection from the retinal ganglion cells to the optic tectum/colliculus. The expression pattern of Eph/ephrin system in opposing gradients both in the retina and the tectum, labels the local addresses on the target and gives specific sensitivities to growth cones according to their topographic origin in the retina. The rigid precision of normal retinotopic mapping has prompted the chemoaffinity hypothesis, positing axonal targeting to be based on fixed biochemical affinities between fibers and targets. However, several lines of evidence have shown that the mapping can adjust to experimentally modified targets with flexibility, demonstrating the robustness of the guidance process. Here we discuss the complex ways the Ephs and ephrins interact allowing to understand how the retinotectal mapping is a precise but also a flexible process.
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Affiliation(s)
- Mara Medori
- CONICET - Universidad de Buenos Aires, Instituto de Biología Celular y Neurociencias "Prof. E. De Robertis" (IBCN); Universidad de Buenos Aires, Facultad de Medicina, Departamento de Biología Celular, Histología, Embriología y Genética, Ciudad Autónoma de Buenos Aires, Argentina
| | - Gonzalo Spelzini
- CONICET - Universidad de Buenos Aires, Instituto de Biología Celular y Neurociencias "Prof. E. De Robertis" (IBCN); Universidad de Buenos Aires, Facultad de Medicina, Departamento de Biología Celular, Histología, Embriología y Genética, Ciudad Autónoma de Buenos Aires, Argentina
| | - Gabriel Scicolone
- CONICET - Universidad de Buenos Aires, Instituto de Biología Celular y Neurociencias "Prof. E. De Robertis" (IBCN); Universidad de Buenos Aires, Facultad de Medicina, Departamento de Biología Celular, Histología, Embriología y Genética, Ciudad Autónoma de Buenos Aires, Argentina
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Regulation of axonal EphA4 forward signaling is involved in the effect of EphA3 on chicken retinal ganglion cell axon growth during retinotectal mapping. Exp Eye Res 2019; 178:46-60. [DOI: 10.1016/j.exer.2018.09.007] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2018] [Revised: 09/06/2018] [Accepted: 09/16/2018] [Indexed: 12/22/2022]
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Combined use of in ovo electroporation and cultured neurons for gene function analysis of embryogenesis in the chicken optic tectum. Neuroreport 2017; 28:1180-1185. [PMID: 28953094 DOI: 10.1097/wnr.0000000000000903] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Chicken embryos are used widely in the fields of developmental biology and neurobiology. The chicken embryo also serves as a model to analyze gene expression and function using in ovo electroporation. Plasmids may be injected into the spinal cord or tectum of the chicken central nervous system by microinjection for electroporation. Here, we developed a novel method that combines in ovo electroporation and neuronal culturing to study gene function in the chicken tectum during embryo development. Our method can be used to study in-vivo and in-vitro exogenous genes' function. In addition, live cell imaging microscopy, immunostaining, and transfection can be used with our method to study neuronal growth, development, neurite growth and retraction, and axonal pathfinding. Our result showed that axons were present in isolated neurons after culturing for 24 h, and cell debris was low after replacing the media at 48 h. Many GFP-expressing neurons were observed in the cultured cells after 48 h. We successfully cultured the neurons for 3 weeks. Together, this method combines in ovo electroporation and neuronal culturing advantages and is more convenient for the gene function analysis.
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Kukreja S, Gautam P, Saxena R, Saxena M, Udaykumar N, Kumar A, Bhatt R, Kumar V, Sen J. Identification of novel candidate regulators of retinotectal map formation through transcriptional profiling of the chick optic tectum. J Comp Neurol 2017; 525:459-477. [PMID: 27410778 DOI: 10.1002/cne.24073] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2015] [Revised: 07/06/2016] [Accepted: 07/08/2016] [Indexed: 11/06/2022]
Abstract
Information from the retina is carried along the visual pathway with accuracy and spatial conservation as a result of topographically mapped axonal connections. The optic tectum in the midbrain is the primary region to which retinal ganglion cells project their axons in the chick. The two primary axes of the retina project independently onto the tectum using different sets of guidance cues to give rise to the retinotectal map. Specificity of the map is determined by attractive or repulsive interactions between molecular tags that are distributed in gradients in the retina and the tectum. Despite several studies, knowledge of the retinotectal guidance molecules is far from being complete. We screened for all molecules that are expressed differentially along the anterior-posterior and medial-lateral axes of the chick tectum using microarray based transcriptional profiling and identified several novel candidate retinotectal guidance molecules. Two such genes, encoding Wnt5a and Raldh2, the synthesizing enzymes for retinoic acid, were further analyzed for their function as putative regulators of retinotectal map formation. Wnt5a and retinoic acid were found to exhibit differential effects on the growth of axons from retinal explants derived from different quadrants of the retina. This screen also yielded a large number of genes expressed in a lamina-specific manner in the tectum, which may have other roles in tectal development. J. Comp. Neurol. 525:459-477, 2017. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Shweta Kukreja
- Department of Biological Sciences and Bioengineering, Indian Institute of Technology Kanpur, Kanpur, Uttar Pradesh, 208016, India.,Shweta Kukreja is now at the Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, MA, 01605
| | - Pratibha Gautam
- Department of Biological Sciences and Bioengineering, Indian Institute of Technology Kanpur, Kanpur, Uttar Pradesh, 208016, India.,Pratibha Gautam is now at the Kusuma School of Biological Sciences, Indian Institute of Technology Delhi, Hauz Khas, New Delhi, 110016, India
| | - Richa Saxena
- Department of Biological Sciences and Bioengineering, Indian Institute of Technology Kanpur, Kanpur, Uttar Pradesh, 208016, India.,Richa Saxena is now at the Central Drug Research Institute, Jankipuram, Lucknow, Uttar Pradesh, 226031, India
| | - Monika Saxena
- Department of Biological Sciences and Bioengineering, Indian Institute of Technology Kanpur, Kanpur, Uttar Pradesh, 208016, India
| | - Niveda Udaykumar
- Department of Biological Sciences and Bioengineering, Indian Institute of Technology Kanpur, Kanpur, Uttar Pradesh, 208016, India
| | - Aditi Kumar
- Department of Biological Sciences and Bioengineering, Indian Institute of Technology Kanpur, Kanpur, Uttar Pradesh, 208016, India
| | - Ritesh Bhatt
- Department of Biological Sciences and Bioengineering, Indian Institute of Technology Kanpur, Kanpur, Uttar Pradesh, 208016, India
| | - Vidur Kumar
- Department of Biological Sciences and Bioengineering, Indian Institute of Technology Kanpur, Kanpur, Uttar Pradesh, 208016, India
| | - Jonaki Sen
- Department of Biological Sciences and Bioengineering, Indian Institute of Technology Kanpur, Kanpur, Uttar Pradesh, 208016, India
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Engrailed homeoproteins in visual system development. Cell Mol Life Sci 2014; 72:1433-45. [PMID: 25432704 PMCID: PMC4366559 DOI: 10.1007/s00018-014-1776-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2014] [Revised: 10/31/2014] [Accepted: 11/06/2014] [Indexed: 12/28/2022]
Abstract
Engrailed is a homeoprotein transcription factor. This family of transcription factors is characterized by their DNA-binding homeodomain and some members, including Engrailed, can transfer between cells and regulate protein translation in addition to gene transcription. Engrailed is intimately involved in the development of the vertebrate visual system. Early expression of Engrailed in dorsal mesencephalon contributes to the development and organization of a visual structure, the optic tectum/superior colliculus. This structure is an important target for retinal ganglion cell axons that carry visual information from the retina. Engrailed regulates the expression of Ephrin axon guidance cues in the tectum/superior colliculus. More recently it has been reported that Engrailed itself acts as an axon guidance cue in synergy with the Ephrin system and is proposed to enhance retinal topographic precision.
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Triplett JW. Molecular guidance of retinotopic map development in the midbrain. Curr Opin Neurobiol 2013; 24:7-12. [PMID: 24492072 DOI: 10.1016/j.conb.2013.07.006] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2013] [Accepted: 07/07/2013] [Indexed: 10/26/2022]
Abstract
Topographic maps are utilized in many sensory and motor systems to efficiently transfer information between brain regions. The retina's projection to the superior colliculus has served as a model for the identification of molecular cues and mechanistic strategies by which topographic maps are formed. Evidence from both in vitro and in vivo studies points to graded cell surface cues playing a central role, but support for axon-axon competition and selective degeneration have also been advanced recently. In combination with mathematical models, these studies suggest that topographic maps are established using a complex combination of strategies to ensure precise connectivity.
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Affiliation(s)
- Jason W Triplett
- Center for Neuroscience Research, Children's National Medical Center, 111 Michigan Avenue, NW, Washington, DC 20010, United States.
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