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Aragona M, Briglia M, Porcino C, Mhalhel K, Cometa M, Germanà PG, Montalbano G, Levanti M, Laurà R, Abbate F, Germanà A, Guerrera MC. Localization of Calretinin, Parvalbumin, and S100 Protein in Nothobranchius guentheri Retina: A Suitable Model for the Retina Aging. Life (Basel) 2023; 13:2050. [PMID: 37895432 PMCID: PMC10608213 DOI: 10.3390/life13102050] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2023] [Revised: 08/05/2023] [Accepted: 09/28/2023] [Indexed: 10/29/2023] Open
Abstract
Calcium-binding proteins (CaBPs) are members of a heterogeneous family of proteins able to buffer intracellular Ca2+ ion concentration. CaBPs are expressed in the central and peripheral nervous system, including a subpopulation of retinal neurons. Since neurons expressing different CaBPs show different susceptibility to degeneration, it could be hypothesized that they are not just markers of different neuronal subpopulations, but that they might be crucial in survival. CaBPs' ability to buffer Ca2+ cytoplasmatic concentration makes them able to defend against a toxic increase in intracellular calcium that can lead to neurodegenerative processes, including those related to aging. An emergent model for aging studies is the annual killifish belonging to the Nothobranchius genus, thanks to its short lifespan. Members of this genus, such as Nothobranchius guentheri, show a retinal stratigraphy similar to that of other actinopterygian fishes and humans. However, according to our knowledge, CaBPs' occurrence and distribution in the retina of N. guentheri have never been investigated before. Therefore, the present study aimed to localize Calretinin N-18, Parvalbumin, and S100 protein (S100p) in the N. guentheri retina with immunohistochemistry methods. The results of the present investigation demonstrate for the first time the occurrence of Calretinin N-18, Parvalbumin, and S100p in N. guentheri retina and, consequently, the potential key role of these CaBPs in the biology of the retinal cells. Hence, the suitability of N. guentheri as a model to study the changes in CaBPs' expression patterns during neurodegenerative processes affecting the retina related both to disease and aging can be assumed.
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Affiliation(s)
| | | | - Caterina Porcino
- Zebrafish Neuromorphology Lab, Department of Veterinary Sciences, University of Messina, 98168 Messina, Italy; (M.A.); (M.B.); (K.M.); (M.C.); (P.G.G.); (G.M.); (M.L.); (R.L.); (F.A.); (A.G.); (M.C.G.)
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Potential Neuroprotective Role of Calretinin-N18 and Calbindin-D28k in the Retina of Adult Zebrafish Exposed to Different Wavelength Lights. Int J Mol Sci 2023; 24:ijms24021087. [PMID: 36674603 PMCID: PMC9862630 DOI: 10.3390/ijms24021087] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2022] [Revised: 11/26/2022] [Accepted: 12/15/2022] [Indexed: 01/08/2023] Open
Abstract
The incidence rates of light-induced retinopathies have increased significantly in the last decades because of continuous exposure to light from different electronic devices. Recent studies showed that exposure to blue light had been related to the pathogenesis of light-induced retinopathies. However, the pathophysiological mechanisms underlying changes induced by light exposure are not fully known yet. In the present study, the effects of exposure to light at different wavelengths with emission peaks in the blue light range (400-500 nm) on the localization of Calretinin-N18 (CaR-N18) and Calbindin-D28K (CaB-D28K) in adult zebrafish retina are studied using double immunofluorescence with confocal laser microscopy. CaB-D28K and CaR-N18 are two homologous cytosolic calcium-binding proteins (CaBPs) implicated in essential process regulation in central and peripheral nervous systems. CaB-D28K and CaR-N18 distributions are investigated to elucidate their potential role in maintaining retinal homeostasis under distinct light conditions and darkness. The results showed that light influences CaB-D28K and CaR-N18 distribution in the retina of adult zebrafish, suggesting that these CaBPs could be involved in the pathophysiology of retinal damage induced by the short-wavelength visible light spectrum.
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Boccuni I, Fairless R. Retinal Glutamate Neurotransmission: From Physiology to Pathophysiological Mechanisms of Retinal Ganglion Cell Degeneration. Life (Basel) 2022; 12:638. [PMID: 35629305 PMCID: PMC9147752 DOI: 10.3390/life12050638] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Revised: 04/22/2022] [Accepted: 04/22/2022] [Indexed: 12/12/2022] Open
Abstract
Glutamate neurotransmission and metabolism are finely modulated by the retinal network, where the efficient processing of visual information is shaped by the differential distribution and composition of glutamate receptors and transporters. However, disturbances in glutamate homeostasis can result in glutamate excitotoxicity, a major initiating factor of common neurodegenerative diseases. Within the retina, glutamate excitotoxicity can impair visual transmission by initiating degeneration of neuronal populations, including retinal ganglion cells (RGCs). The vulnerability of RGCs is observed not just as a result of retinal diseases but has also been ascribed to other common neurodegenerative and peripheral diseases. In this review, we describe the vulnerability of RGCs to glutamate excitotoxicity and the contribution of different glutamate receptors and transporters to this. In particular, we focus on the N-methyl-d-aspartate (NMDA) receptor as the major effector of glutamate-induced mechanisms of neurodegeneration, including impairment of calcium homeostasis, changes in gene expression and signalling, and mitochondrial dysfunction, as well as the role of endoplasmic reticular stress. Due to recent developments in the search for modulators of NMDA receptor signalling, novel neuroprotective strategies may be on the horizon.
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Affiliation(s)
- Isabella Boccuni
- Institute for Physiology and Pathophysiology, Heidelberg University, 69120 Heidelberg, Germany
- Department of Neurology, University Clinic Heidelberg, 69120 Heidelberg, Germany;
| | - Richard Fairless
- Department of Neurology, University Clinic Heidelberg, 69120 Heidelberg, Germany;
- Clinical Cooperation Unit (CCU) Neurooncology, German Cancer Consortium (DKTK), German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany
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Li Q, Zhu H, Fan M, Sun J, Reinach PS, Wang Y, Qu J, Zhou X, Zhao F. Form-deprivation myopia downregulates calcium levels in retinal horizontal cells in mice. Exp Eye Res 2022; 218:109018. [PMID: 35240197 DOI: 10.1016/j.exer.2022.109018] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2021] [Revised: 02/14/2022] [Accepted: 02/25/2022] [Indexed: 11/25/2022]
Abstract
The process of eye axis lengthening in myopic eyes is regulated by multiple mechanisms in the retina, and horizontal cells (HCs) are an essential interneuron in the visual regulatory system. Wherein intracellular Ca2+ plays an important role in the events involved in the regulatory role of HCs in the retinal neural network. It is unknown if intracellular Ca2+ regulation in HCs mediates changes in the retinal neural network during myopia progression. We describe here a novel calcium fluorescence indicator system that monitors HCs' intracellular Ca2+ levels during form-deprivation myopia (FDM) in mice. AAV injection of GCaMP6s, as a protein calcium sensor, into a Gja10-Cre mouse monitored the changes in Ca2+signaling in HC that accompany FDM progression in mice. An alternative Gja10-Cre/Ai96-GCaMP6s mouse model was created by cross mating Gja10-Cre with Ai96 mice. Immunofluorescence imaging and live imaging of the retinal cells verified the identity of these animal models. Changes in retinal horizontal cellular Ca2+ levels were resolved during FDM development. The numbers of GCaMP6s and the proportion of HCs were tracked based on profiling changes in GCaMP6s+calbindin+/calbindin+ coimmunostaining patterns. They significantly decreased more after either two days (P < 0.01) or two weeks (P < 0.001) in form deprived eyes than in the untreated fellow eyes. These decreases in their proportion reached significance only in the retinal central region rather than also in the retinal periphery. A novel approach employing a GCaMP6s mouse model was developed that may ultimately clarify if HCs mediate Ca2+ signals that contribute to controlling FDM progression in mice. The results indicate so far that FDM progression is associated with declines in HC Ca2+ signaling activity.
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Affiliation(s)
- Qihang Li
- School of Optometry and Ophthalmology and Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, China; State Key Laboratory of Optometry, Ophthalmology and Vision Science, Wenzhou, Zhejiang, China
| | - He Zhu
- School of Optometry and Ophthalmology and Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, China; State Key Laboratory of Optometry, Ophthalmology and Vision Science, Wenzhou, Zhejiang, China
| | - Miaomiao Fan
- School of Optometry and Ophthalmology and Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, China; State Key Laboratory of Optometry, Ophthalmology and Vision Science, Wenzhou, Zhejiang, China
| | - Jing Sun
- School of Optometry and Ophthalmology and Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, China; State Key Laboratory of Optometry, Ophthalmology and Vision Science, Wenzhou, Zhejiang, China
| | - Peter S Reinach
- School of Optometry and Ophthalmology and Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, China; State Key Laboratory of Optometry, Ophthalmology and Vision Science, Wenzhou, Zhejiang, China
| | - Yuhan Wang
- School of Optometry and Ophthalmology and Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, China; State Key Laboratory of Optometry, Ophthalmology and Vision Science, Wenzhou, Zhejiang, China
| | - Jia Qu
- School of Optometry and Ophthalmology and Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, China; State Key Laboratory of Optometry, Ophthalmology and Vision Science, Wenzhou, Zhejiang, China; Research Unit of Myopia Basic Research and Clinical Prevention and Control, Chinese Academy of Medical Sciences (2019RU025), Wenzhou, Zhejiang, China; Oujiang Laboratory, Zhejiang Lab for Regenerative Medicine, Vision and Brain Health, Wenzhou, Zhejiang, China
| | - Xiangtian Zhou
- School of Optometry and Ophthalmology and Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, China; State Key Laboratory of Optometry, Ophthalmology and Vision Science, Wenzhou, Zhejiang, China; Research Unit of Myopia Basic Research and Clinical Prevention and Control, Chinese Academy of Medical Sciences (2019RU025), Wenzhou, Zhejiang, China; Oujiang Laboratory, Zhejiang Lab for Regenerative Medicine, Vision and Brain Health, Wenzhou, Zhejiang, China.
| | - Fuxin Zhao
- School of Optometry and Ophthalmology and Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, China; State Key Laboratory of Optometry, Ophthalmology and Vision Science, Wenzhou, Zhejiang, China.
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Kelemen K, Szilágyi T. New Approach for Untangling the Role of Uncommon Calcium-Binding Proteins in the Central Nervous System. Brain Sci 2021. [PMID: 34069107 DOI: 10.3390/brainsci11050634ht] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/30/2023] Open
Abstract
Although Ca2+ ion plays an essential role in cellular physiology, calcium-binding proteins (CaBPs) were long used for mainly as immunohistochemical markers of specific cell types in different regions of the central nervous system. They are a heterogeneous and wide-ranging group of proteins. Their function was studied intensively in the last two decades and a tremendous amount of information was gathered about them. Girard et al. compiled a comprehensive list of the gene-expression profiles of the entire EF-hand gene superfamily in the murine brain. We selected from this database those CaBPs which are related to information processing and/or neuronal signalling, have a Ca2+-buffer activity, Ca2+-sensor activity, modulator of Ca2+-channel activity, or a yet unknown function. In this way we created a gene function-based selection of the CaBPs. We cross-referenced these findings with publicly available, high-quality RNA-sequencing and in situ hybridization databases (Human Protein Atlas (HPA), Brain RNA-seq database and Allen Brain Atlas integrated into the HPA) and created gene expression heat maps of the regional and cell type-specific expression levels of the selected CaBPs. This represents a useful tool to predict and investigate different expression patterns and functions of the less-known CaBPs of the central nervous system.
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Affiliation(s)
- Krisztina Kelemen
- Department of Physiology, Doctoral School, Faculty of Medicine, George Emil Palade University of Medicine, Pharmacy, Science, and Technology of Targu Mures, 540142 Târgu Mureș, Romania
| | - Tibor Szilágyi
- Department of Physiology, Doctoral School, Faculty of Medicine, George Emil Palade University of Medicine, Pharmacy, Science, and Technology of Targu Mures, 540142 Târgu Mureș, Romania
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Kelemen K, Szilágyi T. New Approach for Untangling the Role of Uncommon Calcium-Binding Proteins in the Central Nervous System. Brain Sci 2021; 11:brainsci11050634. [PMID: 34069107 PMCID: PMC8156796 DOI: 10.3390/brainsci11050634] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Revised: 05/09/2021] [Accepted: 05/10/2021] [Indexed: 02/07/2023] Open
Abstract
Although Ca2+ ion plays an essential role in cellular physiology, calcium-binding proteins (CaBPs) were long used for mainly as immunohistochemical markers of specific cell types in different regions of the central nervous system. They are a heterogeneous and wide-ranging group of proteins. Their function was studied intensively in the last two decades and a tremendous amount of information was gathered about them. Girard et al. compiled a comprehensive list of the gene-expression profiles of the entire EF-hand gene superfamily in the murine brain. We selected from this database those CaBPs which are related to information processing and/or neuronal signalling, have a Ca2+-buffer activity, Ca2+-sensor activity, modulator of Ca2+-channel activity, or a yet unknown function. In this way we created a gene function-based selection of the CaBPs. We cross-referenced these findings with publicly available, high-quality RNA-sequencing and in situ hybridization databases (Human Protein Atlas (HPA), Brain RNA-seq database and Allen Brain Atlas integrated into the HPA) and created gene expression heat maps of the regional and cell type-specific expression levels of the selected CaBPs. This represents a useful tool to predict and investigate different expression patterns and functions of the less-known CaBPs of the central nervous system.
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Masri RA, Grünert U, Martin PR. Analysis of Parvocellular and Magnocellular Visual Pathways in Human Retina. J Neurosci 2020; 40:8132-8148. [PMID: 33009001 PMCID: PMC7574660 DOI: 10.1523/jneurosci.1671-20.2020] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 08/26/2020] [Accepted: 09/22/2020] [Indexed: 12/18/2022] Open
Abstract
Two main subcortical pathways serving conscious visual perception are the midget-parvocellular (P), and the parasol-magnocellular (M) pathways. It is generally accepted that the P pathway serves red-green color vision, but the relative contribution of P and M pathways to spatial vision is a long-standing and unresolved issue. Here, we mapped the spatial sampling properties of P and M pathways across the human retina. Data were obtained from immunolabeled vertical sections of six postmortem male and female human donor retinas and imaged using high-resolution microscopy. Cone photoreceptors, OFF-midget bipolar cells (P pathway), OFF-diffuse bipolar (DB) types DB3a and DB3b (M pathway), and ganglion cells were counted along the temporal horizontal meridian, taking foveal spatial distortions (postreceptoral displacements) into account. We found that the density of OFF-midget bipolar and OFF-midget ganglion cells can support one-to-one connections to 1.05-mm (3.6°) eccentricity. One-to-one connections of cones to OFF-midget bipolar cells are present to at least 10-mm (35°) eccentricity. The OFF-midget ganglion cell array acuity is well-matched to photopic spatial acuity measures throughout the central 35°, but the OFF-parasol array acuity is well below photopic spatial acuity, supporting the view that the P pathway underlies high-acuity spatial vision. Outside the fovea, array acuity of both OFF-midget and OFF-DB cells exceeds psychophysical measures of photopic spatial acuity. We conclude that parasol and midget pathway bipolar cells deliver high-acuity spatial signals to the inner plexiform layer, but outside the fovea, this spatial resolution is lost at the level of ganglion cells.SIGNIFICANCE STATEMENT We make accurate maps of the spatial density and distribution of neurons in the human retina to aid in understanding human spatial vision, interpretation of diagnostic tests, and the implementation of therapies for retinal diseases. Here, we map neurons involved with the midget-parvocellular (P pathway) and parasol-magnocellular (M pathway) through human retina. We find that P-type bipolar cells outnumber M-type bipolar cells at all eccentricities. We show that cone photoreceptors and P-type pathway bipolar cells are tightly connected throughout the retina, but that spatial resolution is lost at the level of the ganglion cells. Overall, the results support the view that the P pathway is specialized to serve both high acuity vision and red-green color vision.
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Affiliation(s)
- Rania A Masri
- Faculty of Medicine and Health, Save Sight Institute and Discipline of Clinical Ophthalmology, The University of Sydney, Sydney, New South Wales 2000, Australia
- Australian Research Council Center of Excellence for Integrative Brain Function, The University of Sydney, Sydney, New South Wales 2000, Australia
| | - Ulrike Grünert
- Faculty of Medicine and Health, Save Sight Institute and Discipline of Clinical Ophthalmology, The University of Sydney, Sydney, New South Wales 2000, Australia
- Australian Research Council Center of Excellence for Integrative Brain Function, The University of Sydney, Sydney, New South Wales 2000, Australia
| | - Paul R Martin
- Faculty of Medicine and Health, Save Sight Institute and Discipline of Clinical Ophthalmology, The University of Sydney, Sydney, New South Wales 2000, Australia
- Australian Research Council Center of Excellence for Integrative Brain Function, The University of Sydney, Sydney, New South Wales 2000, Australia
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Kovács-Öller T, Szarka G, Tengölics ÁJ, Ganczer A, Balogh B, Szabó-Meleg E, Nyitrai M, Völgyi B. Spatial Expression Pattern of the Major Ca 2+-Buffer Proteins in Mouse Retinal Ganglion Cells. Cells 2020; 9:cells9040792. [PMID: 32218175 PMCID: PMC7226302 DOI: 10.3390/cells9040792] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2020] [Revised: 03/20/2020] [Accepted: 03/24/2020] [Indexed: 01/10/2023] Open
Abstract
The most prevalent Ca2+-buffer proteins (CaBPs: parvalbumin—PV; calbindin—CaB; calretinin—CaR) are widely expressed by various neurons throughout the brain, including the retinal ganglion cells (RGCs). Even though their retinal expression has been extensively studied, a coherent assessment of topographical variations is missing. To examine this, we performed immunohistochemistry (IHC) in mouse retinas. We found variability in the expression levels and cell numbers for CaR, with stronger and more numerous labels in the dorso-central area. CaBP+ cells contributed to RGCs with all soma sizes, indicating heterogeneity. We separated four to nine RGC clusters in each area based on expression levels and soma sizes. Besides the overall high variety in cluster number and size, the peripheral half of the temporal retina showed the greatest cluster number, indicating a better separation of RGC subtypes there. Multiple labels showed that 39% of the RGCs showed positivity for a single CaBP, 30% expressed two CaBPs, 25% showed no CaBP expression, and 6% expressed all three proteins. Finally, we observed an inverse relation between CaB and CaR expression levels in CaB/CaR dual- and CaB/CaR/PV triple-labeled RGCs, suggesting a mutual complementary function.
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Affiliation(s)
- Tamás Kovács-Öller
- János Szentágothai Research Centre, University of Pécs, 7624 Pécs, Hungary; (G.S.); (A.G.); (B.B.); (E.S.-M.); (M.N.); (B.V.)
- Retinal Electrical Synapses Research Group, National Brain Research Program (NAP 2.0), Hungarian Academy of Sciences, 1051 Budapest, Hungary
- Department of Experimental Zoology and Neurobiology, University of Pécs, 7624 Pécs, Hungary
- Medical School, University of Pécs, 7624 Pécs, Hungary
- Correspondence:
| | - Gergely Szarka
- János Szentágothai Research Centre, University of Pécs, 7624 Pécs, Hungary; (G.S.); (A.G.); (B.B.); (E.S.-M.); (M.N.); (B.V.)
- Retinal Electrical Synapses Research Group, National Brain Research Program (NAP 2.0), Hungarian Academy of Sciences, 1051 Budapest, Hungary
- Department of Experimental Zoology and Neurobiology, University of Pécs, 7624 Pécs, Hungary
| | - Ádám J. Tengölics
- János Szentágothai Research Centre, University of Pécs, 7624 Pécs, Hungary; (G.S.); (A.G.); (B.B.); (E.S.-M.); (M.N.); (B.V.)
- Retinal Electrical Synapses Research Group, National Brain Research Program (NAP 2.0), Hungarian Academy of Sciences, 1051 Budapest, Hungary
- Department of Experimental Zoology and Neurobiology, University of Pécs, 7624 Pécs, Hungary
| | - Alma Ganczer
- János Szentágothai Research Centre, University of Pécs, 7624 Pécs, Hungary; (G.S.); (A.G.); (B.B.); (E.S.-M.); (M.N.); (B.V.)
- Retinal Electrical Synapses Research Group, National Brain Research Program (NAP 2.0), Hungarian Academy of Sciences, 1051 Budapest, Hungary
- Department of Experimental Zoology and Neurobiology, University of Pécs, 7624 Pécs, Hungary
| | - Boglárka Balogh
- János Szentágothai Research Centre, University of Pécs, 7624 Pécs, Hungary; (G.S.); (A.G.); (B.B.); (E.S.-M.); (M.N.); (B.V.)
- Retinal Electrical Synapses Research Group, National Brain Research Program (NAP 2.0), Hungarian Academy of Sciences, 1051 Budapest, Hungary
- Department of Experimental Zoology and Neurobiology, University of Pécs, 7624 Pécs, Hungary
| | - Edina Szabó-Meleg
- János Szentágothai Research Centre, University of Pécs, 7624 Pécs, Hungary; (G.S.); (A.G.); (B.B.); (E.S.-M.); (M.N.); (B.V.)
- Medical School, University of Pécs, 7624 Pécs, Hungary
| | - Miklós Nyitrai
- János Szentágothai Research Centre, University of Pécs, 7624 Pécs, Hungary; (G.S.); (A.G.); (B.B.); (E.S.-M.); (M.N.); (B.V.)
- Medical School, University of Pécs, 7624 Pécs, Hungary
| | - Béla Völgyi
- János Szentágothai Research Centre, University of Pécs, 7624 Pécs, Hungary; (G.S.); (A.G.); (B.B.); (E.S.-M.); (M.N.); (B.V.)
- Retinal Electrical Synapses Research Group, National Brain Research Program (NAP 2.0), Hungarian Academy of Sciences, 1051 Budapest, Hungary
- Department of Experimental Zoology and Neurobiology, University of Pécs, 7624 Pécs, Hungary
- Medical School, University of Pécs, 7624 Pécs, Hungary
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Lee SCS, Martin PR, Grünert U. Topography of Neurons in the Rod Pathway of Human Retina. Invest Ophthalmol Vis Sci 2019; 60:2848-2859. [PMID: 31260035 DOI: 10.1167/iovs.19-27217] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose The objective of this study was to map the distribution and density of the three major components of the classical scotopic "night vision" pathway (rods, rod bipolar, and AII amacrine cells) in postmortem human retinas. Methods Four postmortem donor eyes (male and female, aged 44-56 years) were used to cut vertical sections through the temporal horizontal meridian. The sections were processed for immunohistochemistry and imaged using high-resolution multichannel confocal microscopy. Rods, rod bipolar, and AII amacrine cells were counted along the temporal horizontal meridian. Two additional retinas were used for intracellular injections. Results Rod peak density is close to 150,000 cells/mm2 at 4 to 5 mm (15° to 20°) eccentricity, declining to below 70,000 cells/mm2 in peripheral retina. Rod bipolar density is lower but follows a similar distribution with peak density near 10,000 cells/mm2 between 2 and 4 mm (7° to 15°) eccentricity declining to below 4000 cells/mm2 in peripheral retina. The peak density of AII amacrine cells (near 4000 cells/mm2) is located close to the fovea, at 0.5- to 2 mm-eccentricity (2° to 7°) and declines to below 1000 cells/mm2 in the periphery. Thus, convergence between rods and AII cells increases from central to peripheral retina. Conclusions Comparison with human psychophysics and ganglion cell density indicates that the spatial resolution of scotopic vision is limited by the AII mosaic at eccentricities below 15° and by the midget ganglion cell mosaic at eccentricities above 15°.
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Affiliation(s)
- Sammy C S Lee
- The University of Sydney, Faculty of Medicine and Health, Save Sight Institute and Discipline of Clinical Ophthalmology, Sydney, New South Wales, Australia.,Australian Research Council Centre of Excellence for Integrative Brain Function, The University of Sydney, Sydney, New South Wales, Australia
| | - Paul R Martin
- The University of Sydney, Faculty of Medicine and Health, Save Sight Institute and Discipline of Clinical Ophthalmology, Sydney, New South Wales, Australia.,Australian Research Council Centre of Excellence for Integrative Brain Function, The University of Sydney, Sydney, New South Wales, Australia
| | - Ulrike Grünert
- The University of Sydney, Faculty of Medicine and Health, Save Sight Institute and Discipline of Clinical Ophthalmology, Sydney, New South Wales, Australia.,Australian Research Council Centre of Excellence for Integrative Brain Function, The University of Sydney, Sydney, New South Wales, Australia
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Telkes I, Kóbor P, Orbán J, Kovács-Öller T, Völgyi B, Buzás P. Connexin-36 distribution and layer-specific topography in the cat retina. Brain Struct Funct 2019; 224:2183-2197. [PMID: 31172263 PMCID: PMC6591202 DOI: 10.1007/s00429-019-01876-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2018] [Accepted: 04/11/2019] [Indexed: 11/29/2022]
Abstract
Connexin-36 (Cx36) is the major constituent of mammalian retinal gap junctions positioned in key signal pathways. Here, we examined the laminar and large-scale topographical distribution of Cx36 punctate immunolabels in the retina of the cat, a classical model of the mammalian visual system. Calretinin-immunoreactive (CaR-IR) cell populations served to outline the nuclear and plexiform layers and to stain specific neuronal populations. CaR-IR cells included horizontal cells in the outer retina, numerous amacrine cells, and scattered cells in the ganglion cell layer. Cx36-IR plaques were found among horizontal cell dendrites albeit without systematic colocalization of the two labels. Diffuse Cx36 immunoreactivity was found in the cytoplasm of AII amacrine cells, but no colocalization of Cx36 plaques was observed with either the perikarya or the long varicose dendrites of the CaR-IR non-AII amacrine cells. Cx36 puncta were seen throughout the entire inner plexiform layer showing their highest density in the ON sublamina. The densities of AII amacrine cell bodies and Cx36 plaques in the ON sublamina were strongly correlated across a wide range of eccentricities suggesting their anatomical association. However, the high number of plaques per AII cell suggests that a considerable fraction of Cx36 gap junctions in the ON sublamina is formed by other cell types than AII amacrine cells drawing attention to extensive but less studied electrically coupled networks.
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Affiliation(s)
- Ildikó Telkes
- Institute of Physiology, Medical School, University of Pécs, Szigeti út 12, Pécs, 7624, Hungary
- Szentágothai Research Centre, University of Pécs, Pécs, 7624, Hungary
- Centre for Neuroscience, University of Pécs, Pécs, 7624, Hungary
| | - Péter Kóbor
- Institute of Physiology, Medical School, University of Pécs, Szigeti út 12, Pécs, 7624, Hungary
- Szentágothai Research Centre, University of Pécs, Pécs, 7624, Hungary
- Centre for Neuroscience, University of Pécs, Pécs, 7624, Hungary
| | - József Orbán
- Szentágothai Research Centre, University of Pécs, Pécs, 7624, Hungary
- Department of Biophysics, Medical School, University of Pécs, Pécs, 7624, Hungary
| | - Tamás Kovács-Öller
- Szentágothai Research Centre, University of Pécs, Pécs, 7624, Hungary
- Department of Experimental Zoology and Neurobiology, University of Pécs, Pécs, 7624, Hungary
- Retinal Electrical Synapses Research Group, MTA-PTE NAP-2, University of Pécs, Pécs, 7624, Hungary
- Centre for Neuroscience, University of Pécs, Pécs, 7624, Hungary
| | - Béla Völgyi
- Szentágothai Research Centre, University of Pécs, Pécs, 7624, Hungary
- Department of Experimental Zoology and Neurobiology, University of Pécs, Pécs, 7624, Hungary
- Retinal Electrical Synapses Research Group, MTA-PTE NAP-2, University of Pécs, Pécs, 7624, Hungary
- Centre for Neuroscience, University of Pécs, Pécs, 7624, Hungary
| | - Péter Buzás
- Institute of Physiology, Medical School, University of Pécs, Szigeti út 12, Pécs, 7624, Hungary.
- Szentágothai Research Centre, University of Pécs, Pécs, 7624, Hungary.
- Centre for Neuroscience, University of Pécs, Pécs, 7624, Hungary.
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11
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Abstract
In primate retina, the calcium-binding protein calbindin is expressed by a variety of neurons including cones, bipolar cells, and amacrine cells but it is not known which type(s) of cell express calbindin in the ganglion cell layer. The present study aimed to identify calbindin-positive cell type(s) in the amacrine and ganglion cell layer of human and marmoset retina using immunohistochemical markers for ganglion cells (RBPMS and melanopsin) and cholinergic amacrine (ChAT) cells. Intracellular injections following immunolabeling was used to reveal the morphology of calbindin-positive cells. In human retina, calbindin-labeled cells in the ganglion cell layer were identified as inner and outer stratifying melanopsin-expressing ganglion cells, and ON ChAT (starburst amacrine) cells. In marmoset, calbindin immunoreactivity in the ganglion cell layer was absent from ganglion cells but present in ON ChAT cells. In the inner nuclear layer of human retina, calbindin was found in melanopsin-expressing displaced ganglion cells and in at least two populations of amacrine cells including about a quarter of the OFF ChAT cells. In marmoset, a very low proportion of OFF ChAT cells was calbindin-positive. These results suggest that in both species there may be two types of OFF ChAT cells. Consistent with previous studies, the ratio of ON to OFF ChAT cells was about 70 to 30 in human and 30 to 70 in marmoset. Our results show that there are species-related differences between different primates with respect to the expression of calbindin.
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12
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Kovács-Öller T, Szarka G, Ganczer A, Tengölics Á, Balogh B, Völgyi B. Expression of Ca 2+-Binding Buffer Proteins in the Human and Mouse Retinal Neurons. Int J Mol Sci 2019; 20:E2229. [PMID: 31067641 PMCID: PMC6539911 DOI: 10.3390/ijms20092229] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2019] [Revised: 04/30/2019] [Accepted: 05/03/2019] [Indexed: 12/31/2022] Open
Abstract
Ca2+-binding buffer proteins (CaBPs) are widely expressed by various neurons throughout the central nervous system (CNS), including the retina. While the expression of CaBPs by photoreceptors, retinal interneurons and the output ganglion cells in the mammalian retina has been extensively studied, a general description is still missing due to the differences between species, developmental expression patterns and study-to-study discrepancies. Furthermore, CaBPs are occasionally located in a compartment-specific manner and two or more CaBPs can be expressed by the same neuron, thereby sharing the labor of Ca2+ buffering in the intracellular milieu. This article reviews this topic by providing a framework on CaBP functional expression by neurons of the mammalian retina with an emphasis on human and mouse retinas and the three most abundant and extensively studied buffer proteins: parvalbumin, calretinin and calbindin.
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Affiliation(s)
- Tamás Kovács-Öller
- János Szentágothai Research Centre, University of Pécs, 7624 Pécs, Hungary.
- Retinal Electrical Synapses Research Group, National Brain Research Program (NAP 2.0), Hungarian Academy of Sciences, 1051 Budapest, Hungary.
- Department of Experimental Zoology and Neurobiology, University of Pécs, 7624 Pécs, Hungary.
- Medical School, University of Pécs, 7624 Pécs, Hungary.
| | - Gergely Szarka
- János Szentágothai Research Centre, University of Pécs, 7624 Pécs, Hungary.
- Retinal Electrical Synapses Research Group, National Brain Research Program (NAP 2.0), Hungarian Academy of Sciences, 1051 Budapest, Hungary.
- Department of Experimental Zoology and Neurobiology, University of Pécs, 7624 Pécs, Hungary.
| | - Alma Ganczer
- János Szentágothai Research Centre, University of Pécs, 7624 Pécs, Hungary.
- Retinal Electrical Synapses Research Group, National Brain Research Program (NAP 2.0), Hungarian Academy of Sciences, 1051 Budapest, Hungary.
- Department of Experimental Zoology and Neurobiology, University of Pécs, 7624 Pécs, Hungary.
| | - Ádám Tengölics
- János Szentágothai Research Centre, University of Pécs, 7624 Pécs, Hungary.
- Retinal Electrical Synapses Research Group, National Brain Research Program (NAP 2.0), Hungarian Academy of Sciences, 1051 Budapest, Hungary.
- Department of Experimental Zoology and Neurobiology, University of Pécs, 7624 Pécs, Hungary.
| | - Boglárka Balogh
- János Szentágothai Research Centre, University of Pécs, 7624 Pécs, Hungary.
- Retinal Electrical Synapses Research Group, National Brain Research Program (NAP 2.0), Hungarian Academy of Sciences, 1051 Budapest, Hungary.
- Department of Experimental Zoology and Neurobiology, University of Pécs, 7624 Pécs, Hungary.
| | - Béla Völgyi
- János Szentágothai Research Centre, University of Pécs, 7624 Pécs, Hungary.
- Retinal Electrical Synapses Research Group, National Brain Research Program (NAP 2.0), Hungarian Academy of Sciences, 1051 Budapest, Hungary.
- Department of Experimental Zoology and Neurobiology, University of Pécs, 7624 Pécs, Hungary.
- Medical School, University of Pécs, 7624 Pécs, Hungary.
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13
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Fairless R, Williams SK, Diem R. Calcium-Binding Proteins as Determinants of Central Nervous System Neuronal Vulnerability to Disease. Int J Mol Sci 2019; 20:ijms20092146. [PMID: 31052285 PMCID: PMC6539299 DOI: 10.3390/ijms20092146] [Citation(s) in RCA: 66] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2019] [Revised: 04/26/2019] [Accepted: 04/27/2019] [Indexed: 12/14/2022] Open
Abstract
Neuronal subpopulations display differential vulnerabilities to disease, but the factors that determine their susceptibility are poorly understood. Toxic increases in intracellular calcium are a key factor in several neurodegenerative processes, with calcium-binding proteins providing an important first line of defense through their ability to buffer incoming calcium, allowing the neuron to quickly achieve homeostasis. Since neurons expressing different calcium-binding proteins have been reported to be differentially susceptible to degeneration, it can be hypothesized that rather than just serving as markers of different neuronal subpopulations, they might actually be a key determinant of survival. In this review, we will summarize some of the evidence that expression of the EF-hand calcium-binding proteins, calbindin, calretinin and parvalbumin, may influence the susceptibility of distinct neuronal subpopulations to disease processes.
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Affiliation(s)
- Richard Fairless
- Department of Neurology, University Clinic Heidelberg, 69120 Heidelberg, Germany.
- Clinical Cooperation Unit (CCU) Neurooncology, German Cancer Consortium (DKTK), German Cancer Research Center (DFKZ), 69120 Heidelberg, Germany.
| | - Sarah K Williams
- Department of Neurology, University Clinic Heidelberg, 69120 Heidelberg, Germany.
- Clinical Cooperation Unit (CCU) Neurooncology, German Cancer Consortium (DKTK), German Cancer Research Center (DFKZ), 69120 Heidelberg, Germany.
| | - Ricarda Diem
- Department of Neurology, University Clinic Heidelberg, 69120 Heidelberg, Germany.
- Clinical Cooperation Unit (CCU) Neurooncology, German Cancer Consortium (DKTK), German Cancer Research Center (DFKZ), 69120 Heidelberg, Germany.
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14
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Kántor O, Szarka G, Benkő Z, Somogyvári Z, Pálfi E, Baksa G, Rácz G, Nitschke R, Debertin G, Völgyi B. Strategic Positioning of Connexin36 Gap Junctions Across Human Retinal Ganglion Cell Dendritic Arbors. Front Cell Neurosci 2018; 12:409. [PMID: 30524239 PMCID: PMC6262005 DOI: 10.3389/fncel.2018.00409] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2018] [Accepted: 10/22/2018] [Indexed: 11/18/2022] Open
Abstract
Connexin36 (Cx36) subunits form gap junctions (GJ) between neurons throughout the central nervous system. Such GJs of the mammalian retina serve the transmission, averaging and correlation of signals prior to conveying visual information to the brain. Retinal GJs have been exhaustively studied in various animal species, however, there is still a perplexing paucity of information regarding the presence and function of human retinal GJs. Particularly little is known about GJ formation of human retinal ganglion cells (hRGCs) due to the limited number of suitable experimental approaches. Compared to the neuronal coupling studies in animal models, where GJ permeable tracer injection is the gold standard method, the post-mortem nature of scarcely available human retinal samples leaves immunohistochemistry as a sole approach to obtain information on hRGC GJs. In this study Lucifer Yellow (LY) dye injections and Cx36 immunohistochemistry were performed in fixed short-post-mortem samples to stain hRGCs with complete dendritic arbors and locate dendritic Cx36 GJs. Subsequent neuronal reconstructions and morphometric analyses revealed that Cx36 plaques had a clear tendency to form clusters and particularly favored terminal dendritic segments.
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Affiliation(s)
- Orsolya Kántor
- Department of Neuroanatomy, Faculty of Medicine, Institute for Anatomy and Cell Biology, Albert-Ludwigs-University Freiburg, Freiburg, Germany.,MTA-PTE NAP 2 Retinal Electrical Synapses Research Group, Pécs, Hungary.,Department of Anatomy, Histology and Embryology, Semmelweis University, Budapest, Hungary
| | - Gergely Szarka
- MTA-PTE NAP 2 Retinal Electrical Synapses Research Group, Pécs, Hungary.,Department of Experimental Zoology and Neurobiology, University of Pécs, Pécs, Hungary.,Center for Neuroscience, University of Pécs, Pécs, Hungary.,János Szentágothai Research Center, University of Pécs, Pécs, Hungary
| | - Zsigmond Benkő
- Complex Systems and Computational Neuroscience Group, Wigner Research Center for Physics, Hungarian Academy of Sciences, Budapest, Hungary
| | - Zoltán Somogyvári
- Complex Systems and Computational Neuroscience Group, Wigner Research Center for Physics, Hungarian Academy of Sciences, Budapest, Hungary
| | - Emese Pálfi
- Department of Anatomy, Histology and Embryology, Semmelweis University, Budapest, Hungary
| | - Gábor Baksa
- Department of Anatomy, Histology and Embryology, Semmelweis University, Budapest, Hungary
| | - Gergely Rácz
- Department of Pathology and Experimental Cancer Research, Semmelweis University, Budapest, Hungary
| | - Roland Nitschke
- Life Imaging Center, Center for Biological Systems Analysis, Albert-Ludwigs University, Freiburg, Germany.,BIOSS Center for Biological Signaling Studies, Albert-Ludwigs-University Freiburg, Freiburg, Germany
| | - Gábor Debertin
- MTA-PTE NAP 2 Retinal Electrical Synapses Research Group, Pécs, Hungary.,Department of Experimental Zoology and Neurobiology, University of Pécs, Pécs, Hungary.,Center for Neuroscience, University of Pécs, Pécs, Hungary.,János Szentágothai Research Center, University of Pécs, Pécs, Hungary
| | - Béla Völgyi
- MTA-PTE NAP 2 Retinal Electrical Synapses Research Group, Pécs, Hungary.,Department of Experimental Zoology and Neurobiology, University of Pécs, Pécs, Hungary.,Center for Neuroscience, University of Pécs, Pécs, Hungary.,János Szentágothai Research Center, University of Pécs, Pécs, Hungary
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15
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Strettoi E, Masri RA, Grünert U. AII amacrine cells in the primate fovea contribute to photopic vision. Sci Rep 2018; 8:16429. [PMID: 30401922 PMCID: PMC6219554 DOI: 10.1038/s41598-018-34621-2] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2018] [Accepted: 10/19/2018] [Indexed: 11/20/2022] Open
Abstract
The AII amacrine cell is known as a key interneuron in the scotopic (night-vision) pathway in the retina. Under scotopic conditions, rod signals are transmitted via rod bipolar cells to AII amacrine cells, which split the rod signal into the OFF (via glycinergic synapses) and the ON pathway (via gap junctions). But the AII amacrine cell also has a “day job”: at high light levels when cones are active, AII connections with ON cone bipolar cells provide crossover inhibition to extend the response range of OFF cone bipolar cells. The question whether AII cells contribute to crossover inhibition in primate fovea (where rods and rod bipolar cells are rare or absent) has not been answered. Here, immunohistochemistry and three-dimensional reconstruction show that calretinin positive cells in the fovea of macaque monkeys and humans have AII morphology and connect to cone bipolar cells. The pattern of AII connections to cone bipolar cells is quantitatively similar to that of AII cells outside the fovea. Our results support the view that in mammalian retina AII cells first evolved to serve cone circuits, then later were co-opted to process scotopic signals subsequent to the evolution of rod bipolar cells.
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Affiliation(s)
| | - Rania A Masri
- Save Sight Institute, Discipline of Clinical Ophthalmology, The University of Sydney, Sydney, NSW, 2000, Australia.,Australian Research Council Centre of Excellence for Integrative Brain Function, The University of Sydney, Sydney, NSW, 2000, Australia
| | - Ulrike Grünert
- Save Sight Institute, Discipline of Clinical Ophthalmology, The University of Sydney, Sydney, NSW, 2000, Australia. .,Australian Research Council Centre of Excellence for Integrative Brain Function, The University of Sydney, Sydney, NSW, 2000, Australia. .,Faculty of Medicine and Health, The University of Sydney, Sydney, Australia.
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16
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Roski C, Langrock C, Körber N, Habermann G, Buse E, Reichenbach A, Pannicke T, Francke M. Comparison of cellular localisation of the Ca2+
-binding proteins calbindin, calretinin and parvalbumin in the retina of four different Macaca
species. Anat Histol Embryol 2018; 47:573-582. [DOI: 10.1111/ahe.12399] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2018] [Revised: 07/18/2018] [Accepted: 08/02/2018] [Indexed: 11/30/2022]
Affiliation(s)
- Christian Roski
- Paul-Flechsig-Institut für Hirnforschung; Universität Leipzig; Leipzig Germany
| | - Christiane Langrock
- Paul-Flechsig-Institut für Hirnforschung; Universität Leipzig; Leipzig Germany
| | - Nicole Körber
- Paul-Flechsig-Institut für Hirnforschung; Universität Leipzig; Leipzig Germany
- Sächsischer Inkubator für klinische Translation (SIKT); Universität Leipzig; Leipzig Germany
| | | | | | - Andreas Reichenbach
- Paul-Flechsig-Institut für Hirnforschung; Universität Leipzig; Leipzig Germany
| | - Thomas Pannicke
- Paul-Flechsig-Institut für Hirnforschung; Universität Leipzig; Leipzig Germany
| | - Mike Francke
- Paul-Flechsig-Institut für Hirnforschung; Universität Leipzig; Leipzig Germany
- Sächsischer Inkubator für klinische Translation (SIKT); Universität Leipzig; Leipzig Germany
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17
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Christiansen AT, Kiilgaard JF, Klemp K, Woldbye DPD, Hannibal J. Localization, distribution, and connectivity of neuropeptide Y in the human and porcine retinas-A comparative study. J Comp Neurol 2018; 526:1877-1895. [DOI: 10.1002/cne.24455] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2017] [Revised: 03/27/2018] [Accepted: 03/29/2018] [Indexed: 12/24/2022]
Affiliation(s)
| | - Jens Folke Kiilgaard
- Department of Ophthalmology; Copenhagen University Hospital, Rigshospitalet; Denmark
| | - Kristian Klemp
- Department of Ophthalmology; Copenhagen University Hospital, Rigshospitalet; Denmark
| | - David Paul Drucker Woldbye
- Laboratory of Neural Plasticity; Center for Neuroscience, Faculty of Health Sciences, University of Copenhagen; Denmark
| | - Jens Hannibal
- Department of Clinical Biochemistry; Copenhagen University Hospital, Bispebjerg Hospital; Copenhagen Denmark
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18
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Dudczig S, Currie PD, Jusuf PR. Developmental and adult characterization of secretagogin expressing amacrine cells in zebrafish retina. PLoS One 2017; 12:e0185107. [PMID: 28949993 PMCID: PMC5614429 DOI: 10.1371/journal.pone.0185107] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2017] [Accepted: 09/06/2017] [Indexed: 12/19/2022] Open
Abstract
Calcium binding proteins show stereotypical expression patterns within diverse neuron types across the central nervous system. Here, we provide a characterization of developmental and adult secretagogin-immunolabelled neurons in the zebrafish retina with an emphasis on co-expression of multiple calcium binding proteins. Secretagogin is a recently identified and cloned member of the F-hand family of calcium binding proteins, which labels distinct neuron populations in the retinas of mammalian vertebrates. Both the adult distribution of secretagogin labeled retinal neurons as well as the developmental expression indicative of the stage of neurogenesis during which this calcium binding protein is expressed was quantified. Secretagogin expression was confined to an amacrine interneuron population in the inner nuclear layer, with monostratified neurites in the center of the inner plexiform layer and a relatively regular soma distribution (regularity index > 2.5 across central–peripheral areas). However, only a subpopulation (~60%) co-labeled with gamma-aminobutyric acid as their neurotransmitter, suggesting that possibly two amacrine subtypes are secretagogin immunoreactive. Quantitative co-labeling analysis with other known amacrine subtype markers including the three main calcium binding proteins parvalbumin, calbindin and calretinin identifies secretagogin immunoreactive neurons as a distinct neuron population. The highest density of secretagogin cells of ~1800 cells / mm2 remained relatively evenly along the horizontal meridian, whilst the density dropped of to 125 cells / mm2 towards the dorsal and ventral periphery. Thus, secretagogin represents a new amacrine label within the zebrafish retina. The developmental expression suggests a possible role in late stage differentiation. This characterization forms the basis of functional studies assessing how the expression of distinct calcium binding proteins might be regulated to compensate for the loss of one of the others.
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Affiliation(s)
- Stefanie Dudczig
- Australian Regenerative Medicine Institute, Monash University, Clayton, VIC, Australia
- School of Biosciences, University of Melbourne, Parkville, VIC, Australia
| | - Peter David Currie
- Australian Regenerative Medicine Institute, Monash University, Clayton, VIC, Australia
| | - Patricia Regina Jusuf
- Australian Regenerative Medicine Institute, Monash University, Clayton, VIC, Australia
- School of Biosciences, University of Melbourne, Parkville, VIC, Australia
- * E-mail:
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19
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Kántor O, Varga A, Nitschke R, Naumann A, Énzsöly A, Lukáts Á, Szabó A, Németh J, Völgyi B. Bipolar cell gap junctions serve major signaling pathways in the human retina. Brain Struct Funct 2017; 222:2603-2624. [PMID: 28070649 DOI: 10.1007/s00429-016-1360-4] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2016] [Accepted: 12/22/2016] [Indexed: 11/26/2022]
Abstract
Connexin36 (Cx36) constituent gap junctions (GJ) throughout the brain connect neurons into functional syncytia. In the retina they underlie the transmission, averaging and correlation of signals prior conveying visual information to the brain. This is the first study that describes retinal bipolar cell (BC) GJs in the human inner retina, whose function is enigmatic even in the examined animal models. Furthermore, a number of unique features (e.g. fovea, trichromacy, midget system) necessitate a reexamination of the animal model results in the human retina. Well-preserved postmortem human samples of this study are allowed to identify Cx36 expressing BCs neurochemically. Results reveal that both rod and cone pathway interneurons display strong Cx36 expression. Rod BC inputs to AII amacrine cells (AC) appear in juxtaposition to AII GJs, thus suggesting a strategic AII cell targeting by rod BCs. Cone BCs serving midget, parasol or koniocellular signaling pathways display a wealth of Cx36 expression to form homologously coupled arrays. In addition, they also establish heterologous GJ contacts to serve an exchange of information between parallel signaling streams. Interestingly, a prominent Cx36 expression was exhibited by midget system BCs that appear to maintain intimate contacts with bistratified BCs serving other pathways. These findings suggest that BC GJs in parallel signaling streams serve both an intra- and inter-pathway exchange of signals in the human retina.
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Affiliation(s)
- Orsolya Kántor
- Department of Neuroanatomy, Faculty of Medicine, Institute for Anatomy and Cell Biology, University of Freiburg, 79104, Freiburg, Germany
- MTA-PTE NAP B Retinal Electrical Synapses Research Group, Pécs, 7624, Hungary
- Department of Anatomy, Histology and Embryology, Semmelweis University, Budapest, 1094, Hungary
| | - Alexandra Varga
- Department of Anatomy, Histology and Embryology, Semmelweis University, Budapest, 1094, Hungary
| | - Roland Nitschke
- Life Imaging Center, Center for Biological Systems Analysis, University of Freiburg, 79104, Freiburg, Germany
- BIOSS Centre for Biological Signaling Studies, University of Freiburg, 79104, Freiburg, Germany
| | - Angela Naumann
- Life Imaging Center, Center for Biological Systems Analysis, University of Freiburg, 79104, Freiburg, Germany
- BIOSS Centre for Biological Signaling Studies, University of Freiburg, 79104, Freiburg, Germany
| | - Anna Énzsöly
- Department of Anatomy, Histology and Embryology, Semmelweis University, Budapest, 1094, Hungary
- Department of Ophthalmology, Semmelweis University, Budapest, 1085, Hungary
| | - Ákos Lukáts
- Department of Anatomy, Histology and Embryology, Semmelweis University, Budapest, 1094, Hungary
| | - Arnold Szabó
- Department of Anatomy, Histology and Embryology, Semmelweis University, Budapest, 1094, Hungary
| | - János Németh
- Department of Ophthalmology, Semmelweis University, Budapest, 1085, Hungary
| | - Béla Völgyi
- MTA-PTE NAP B Retinal Electrical Synapses Research Group, Pécs, 7624, Hungary.
- Department of Experimental Zoology and Neurobiology, University of Pécs, Pécs, 7624, Hungary.
- János Szentágothai Research Center, University of Pécs, Ifjúság street 20, Pécs, 7624, Hungary.
- Department of Ophthalmology, New York University Langone Medical Center, New York, NY, 10016, USA.
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20
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Kovács-Öller T, Debertin G, Balogh M, Ganczer A, Orbán J, Nyitrai M, Balogh L, Kántor O, Völgyi B. Connexin36 Expression in the Mammalian Retina: A Multiple-Species Comparison. Front Cell Neurosci 2017; 11:65. [PMID: 28337128 PMCID: PMC5343066 DOI: 10.3389/fncel.2017.00065] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2016] [Accepted: 02/23/2017] [Indexed: 11/23/2022] Open
Abstract
Much knowledge about interconnection of human retinal neurons is inferred from results on animal models. Likewise, there is a lack of information on human retinal electrical synapses/gap junctions (GJ). Connexin36 (Cx36) forms GJs in both the inner and outer plexiform layers (IPL and OPL) in most species including humans. However, a comparison of Cx36 GJ distribution in retinas of humans and popular animal models has not been presented. To this end a multiple-species comparison was performed in retinas of 12 mammals including humans to survey the Cx36 distribution. Areas of retinal specializations were avoided (e.g., fovea, visual streak, area centralis), thus observed Cx36 distribution differences were not attributed to these species-specific architecture of central retinal areas. Cx36 was expressed in both synaptic layers in all examined retinas. Cx36 plaques displayed an inhomogenous IPL distribution favoring the ON sublamina, however, this feature was more pronounced in the human, swine and guinea pig while it was less obvious in the rabbit, squirrel monkey, and ferret retinas. In contrast to the relative conservative Cx36 distribution in the IPL, the labels in the OPL varied considerably among mammals. In general, OPL plaques were rare and rather small in rod dominant carnivores and rodents, whereas the human and the cone rich guinea pig retinas displayed robust Cx36 labels. This survey presented that the human retina displayed two characteristic features, a pronounced ON dominance of Cx36 plaques in the IPL and prevalent Cx36 plaque conglomerates in the OPL. While many species showed either of these features, only the guinea pig retina shared both. The observed similarities and subtle differences in Cx36 plaque distribution across mammals do not correspond to evolutionary distances but may reflect accomodation to lifestyles of examined species.
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Affiliation(s)
- Tamás Kovács-Öller
- Department of Experimental Zoology and Neurobiology, University of PécsPécs, Hungary; János Szentágothai Research CenterPécs, Hungary; Retinal Electrical Synapses Research Group, Hungarian Academy of Sciences (MTA-PTE NAP B)Pécs, Hungary
| | - Gábor Debertin
- Department of Experimental Zoology and Neurobiology, University of PécsPécs, Hungary; János Szentágothai Research CenterPécs, Hungary; Retinal Electrical Synapses Research Group, Hungarian Academy of Sciences (MTA-PTE NAP B)Pécs, Hungary
| | - Márton Balogh
- Department of Experimental Zoology and Neurobiology, University of PécsPécs, Hungary; János Szentágothai Research CenterPécs, Hungary; Retinal Electrical Synapses Research Group, Hungarian Academy of Sciences (MTA-PTE NAP B)Pécs, Hungary
| | - Alma Ganczer
- Department of Experimental Zoology and Neurobiology, University of PécsPécs, Hungary; János Szentágothai Research CenterPécs, Hungary; Retinal Electrical Synapses Research Group, Hungarian Academy of Sciences (MTA-PTE NAP B)Pécs, Hungary
| | - József Orbán
- János Szentágothai Research CenterPécs, Hungary; Department of Biophysics, University of PécsPécs, Hungary; High-Field Terahertz Research Group, Hungarian Academy of Sciences (MTA-PTE)Pécs, Hungary
| | - Miklós Nyitrai
- János Szentágothai Research CenterPécs, Hungary; Department of Biophysics, University of PécsPécs, Hungary; Nuclear-Mitochondrial Interactions Research Group, Hungarian Academy of Sciences (MTA-PTE)Pécs, Hungary
| | - Lajos Balogh
- National Research Institute for Radiobiology and Radiohygiene Budapest, Hungary
| | - Orsolya Kántor
- Retinal Electrical Synapses Research Group, Hungarian Academy of Sciences (MTA-PTE NAP B)Pécs, Hungary; Department of Anatomy, Histology and Embryology, Semmelweis UniversityBudapest, Hungary; Department of Neuroanatomy, Institute for Anatomy and Cell Biology, Faculty of Medicine, University of FreiburgFreiburg, Germany
| | - Béla Völgyi
- Department of Experimental Zoology and Neurobiology, University of PécsPécs, Hungary; János Szentágothai Research CenterPécs, Hungary; Retinal Electrical Synapses Research Group, Hungarian Academy of Sciences (MTA-PTE NAP B)Pécs, Hungary; Department of Ophthalmology, New York University Langone Medical Center, New YorkNY, USA
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21
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Country MW, Jonz MG. Calcium dynamics and regulation in horizontal cells of the vertebrate retina: lessons from teleosts. J Neurophysiol 2017; 117:523-536. [PMID: 27832601 PMCID: PMC5288477 DOI: 10.1152/jn.00585.2016] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2016] [Accepted: 11/02/2016] [Indexed: 01/20/2023] Open
Abstract
Horizontal cells (HCs) are inhibitory interneurons of the vertebrate retina. Unlike typical neurons, HCs are chronically depolarized in the dark, leading to a constant influx of Ca2+ Therefore, mechanisms of Ca2+ homeostasis in HCs must differ from neurons elsewhere in the central nervous system, which undergo excitotoxicity when they are chronically depolarized or stressed with Ca2+ HCs are especially well characterized in teleost fish and have been used to unlock mysteries of the vertebrate retina for over one century. More recently, mammalian models of the retina have been increasingly informative for HC physiology. We draw from both teleost and mammalian models in this review, using a comparative approach to examine what is known about Ca2+ pathways in vertebrate HCs. We begin with a survey of Ca2+-permeable ion channels, exchangers, and pumps and summarize Ca2+ influx and efflux pathways, buffering, and intracellular stores. This includes evidence for Ca2+-permeable α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors and N-methyl-d-aspartate receptors and for voltage-gated Ca2+ channels. Special attention is given to interactions between ion channels, to differences among species, and in which subtypes of HCs these channels have been found. We then discuss a number of unresolved issues pertaining to Ca2+ dynamics in HCs, including a potential role for Ca2+ in feedback to photoreceptors, the role for Ca2+-induced Ca2+ release, and the properties and functions of Ca2+-based action potentials. This review aims to highlight the unique Ca2+ dynamics in HCs, as these are inextricably tied to retinal function.
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Affiliation(s)
- Michael W Country
- Department of Biology, University of Ottawa, Ottawa, Ontario, Canada
| | - Michael G Jonz
- Department of Biology, University of Ottawa, Ottawa, Ontario, Canada
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