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Ganczer A, Szarka G, Balogh M, Hoffmann G, Tengölics ÁJ, Kenyon G, Kovács-Öller T, Völgyi B. Transience of the Retinal Output Is Determined by a Great Variety of Circuit Elements. Cells 2022; 11:cells11050810. [PMID: 35269432 PMCID: PMC8909309 DOI: 10.3390/cells11050810] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Revised: 02/21/2022] [Accepted: 02/23/2022] [Indexed: 02/06/2023] Open
Abstract
Retinal ganglion cells (RGCs) encrypt stimulus features of the visual scene in action potentials and convey them toward higher visual centers in the brain. Although there are many visual features to encode, our recent understanding is that the ~46 different functional subtypes of RGCs in the retina share this task. In this scheme, each RGC subtype establishes a separate, parallel signaling route for a specific visual feature (e.g., contrast, the direction of motion, luminosity), through which information is conveyed. The efficiency of encoding depends on several factors, including signal strength, adaptational levels, and the actual efficacy of the underlying retinal microcircuits. Upon collecting inputs across their respective receptive field, RGCs perform further analysis (e.g., summation, subtraction, weighting) before they generate the final output spike train, which itself is characterized by multiple different features, such as the number of spikes, the inter-spike intervals, response delay, and the rundown time (transience) of the response. These specific kinetic features are essential for target postsynaptic neurons in the brain in order to effectively decode and interpret signals, thereby forming visual perception. We review recent knowledge regarding circuit elements of the mammalian retina that participate in shaping RGC response transience for optimal visual signaling.
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Affiliation(s)
- Alma Ganczer
- Szentágothai Research Centre, University of Pécs, H-7624 Pécs, Hungary; (A.G.); (G.S.); (M.B.); (G.H.); (Á.J.T.); (T.K.-Ö.)
- Department of Experimental Zoology and Neurobiology, University of Pécs, H-7624 Pécs, Hungary
- MTA-PTE NAP 2 Retinal Electrical Synapses Research Group, H-7624 Pécs, Hungary
- Center for Neuroscience, University of Pécs, H-7624 Pécs, Hungary
| | - Gergely Szarka
- Szentágothai Research Centre, University of Pécs, H-7624 Pécs, Hungary; (A.G.); (G.S.); (M.B.); (G.H.); (Á.J.T.); (T.K.-Ö.)
- Department of Experimental Zoology and Neurobiology, University of Pécs, H-7624 Pécs, Hungary
- MTA-PTE NAP 2 Retinal Electrical Synapses Research Group, H-7624 Pécs, Hungary
- Center for Neuroscience, University of Pécs, H-7624 Pécs, Hungary
| | - Márton Balogh
- Szentágothai Research Centre, University of Pécs, H-7624 Pécs, Hungary; (A.G.); (G.S.); (M.B.); (G.H.); (Á.J.T.); (T.K.-Ö.)
- Department of Experimental Zoology and Neurobiology, University of Pécs, H-7624 Pécs, Hungary
- MTA-PTE NAP 2 Retinal Electrical Synapses Research Group, H-7624 Pécs, Hungary
- Center for Neuroscience, University of Pécs, H-7624 Pécs, Hungary
| | - Gyula Hoffmann
- Szentágothai Research Centre, University of Pécs, H-7624 Pécs, Hungary; (A.G.); (G.S.); (M.B.); (G.H.); (Á.J.T.); (T.K.-Ö.)
- Department of Experimental Zoology and Neurobiology, University of Pécs, H-7624 Pécs, Hungary
- MTA-PTE NAP 2 Retinal Electrical Synapses Research Group, H-7624 Pécs, Hungary
- Center for Neuroscience, University of Pécs, H-7624 Pécs, Hungary
| | - Ádám Jonatán Tengölics
- Szentágothai Research Centre, University of Pécs, H-7624 Pécs, Hungary; (A.G.); (G.S.); (M.B.); (G.H.); (Á.J.T.); (T.K.-Ö.)
- Department of Experimental Zoology and Neurobiology, University of Pécs, H-7624 Pécs, Hungary
- MTA-PTE NAP 2 Retinal Electrical Synapses Research Group, H-7624 Pécs, Hungary
- Center for Neuroscience, University of Pécs, H-7624 Pécs, Hungary
| | - Garrett Kenyon
- Los Alamos National Laboratory, Computer & Computational Science Division, Los Alamos, NM 87545, USA;
| | - Tamás Kovács-Öller
- Szentágothai Research Centre, University of Pécs, H-7624 Pécs, Hungary; (A.G.); (G.S.); (M.B.); (G.H.); (Á.J.T.); (T.K.-Ö.)
- Department of Experimental Zoology and Neurobiology, University of Pécs, H-7624 Pécs, Hungary
- MTA-PTE NAP 2 Retinal Electrical Synapses Research Group, H-7624 Pécs, Hungary
- Center for Neuroscience, University of Pécs, H-7624 Pécs, Hungary
| | - Béla Völgyi
- Szentágothai Research Centre, University of Pécs, H-7624 Pécs, Hungary; (A.G.); (G.S.); (M.B.); (G.H.); (Á.J.T.); (T.K.-Ö.)
- Department of Experimental Zoology and Neurobiology, University of Pécs, H-7624 Pécs, Hungary
- MTA-PTE NAP 2 Retinal Electrical Synapses Research Group, H-7624 Pécs, Hungary
- Center for Neuroscience, University of Pécs, H-7624 Pécs, Hungary
- Correspondence:
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Pöstyéni E, Ganczer A, Kovács-Valasek A, Gabriel R. Relevance of Peptide Homeostasis in Metabolic Retinal Degenerative Disorders: Curative Potential in Genetically Modified Mice. Front Pharmacol 2022; 12:808315. [PMID: 35095518 PMCID: PMC8793341 DOI: 10.3389/fphar.2021.808315] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2021] [Accepted: 12/20/2021] [Indexed: 11/19/2022] Open
Abstract
The mammalian retina contains approximately 30 neuropeptides that are synthetized by different neuronal cell populations, glia, and the pigmented epithelium. The presence of these neuropeptides leaves a mark on normal retinal molecular processes and physiology, and they are also crucial in fighting various pathologies (e.g., diabetic retinopathy, ischemia, age-related pathologies, glaucoma) because of their protective abilities. Retinal pathologies of different origin (metabolic, genetic) are extensively investigated by genetically manipulated in vivo mouse models that help us gain a better understanding of the molecular background of these pathomechanisms. These models offer opportunities to manipulate gene expression in different cell types to help reveal their roles in the preservation of retinal health or identify malfunction during diseases. In order to assess the current status of transgenic technologies available, we have conducted a literature survey focused on retinal disorders of metabolic origin, zooming in on the role of retinal neuropeptides in diabetic retinopathy and ischemia. First, we identified those neuropeptides that are most relevant to retinal pathologies in humans and the two clinically most relevant models, mice and rats. Then we continued our analysis with metabolic disorders, examining neuropeptide-related pathways leading to systemic or cellular damage and rescue. Last but not least, we reviewed the available literature on genetically modified mouse strains to understand how the manipulation of a single element of any given pathway (e.g., signal molecules, receptors, intracellular signaling pathways) could lead either to the worsening of disease conditions or, more frequently, to substantial improvements in retinal health. Most attention was given to studies which reported successful intervention against specific disorders. For these experiments, a detailed evaluation will be given and the possible role of converging intracellular pathways will be discussed. Using these converging intracellular pathways, curative effects of peptides could potentially be utilized in fighting metabolic retinal disorders.
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Affiliation(s)
- Etelka Pöstyéni
- Department of Experimental Zoology and Neurobiology, University of Pécs, Pécs, Hungary
| | - Alma Ganczer
- Department of Experimental Zoology and Neurobiology, University of Pécs, Pécs, Hungary.,János Szentágothai Research Centre, University of Pécs, Pécs, Hungary
| | - Andrea Kovács-Valasek
- Department of Experimental Zoology and Neurobiology, University of Pécs, Pécs, Hungary
| | - Robert Gabriel
- Department of Experimental Zoology and Neurobiology, University of Pécs, Pécs, Hungary.,János Szentágothai Research Centre, University of Pécs, Pécs, Hungary
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Szarka G, Balogh M, Tengölics ÁJ, Ganczer A, Völgyi B, Kovács-Öller T. The role of gap junctions in cell death and neuromodulation in the retina. Neural Regen Res 2021; 16:1911-1920. [PMID: 33642359 PMCID: PMC8343308 DOI: 10.4103/1673-5374.308069] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Revised: 10/14/2020] [Accepted: 01/11/2021] [Indexed: 12/26/2022] Open
Abstract
Vision altering diseases, such as glaucoma, diabetic retinopathy, age-related macular degeneration, myopia, retinal vascular disease, traumatic brain injuries and others cripple many lives and are projected to continue to cause anguish in the foreseeable future. Gap junctions serve as an emerging target for neuromodulation and possible regeneration as they directly connect healthy and/or diseased cells, thereby playing a crucial role in pathophysiology. Since they are permeable for macromolecules, able to cross the cellular barriers, they show duality in illness as a cause and as a therapeutic target. In this review, we take recent advancements in gap junction neuromodulation (pharmacological blockade, gene therapy, electrical and light stimulation) into account, to show the gap junction's role in neuronal cell death and the possible routes of rescuing neuronal and glial cells in the retina succeeding illness or injury.
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Affiliation(s)
- Gergely Szarka
- János Szentágothai Research Centre, University of Pécs, Pécs, Hungary
- Retinal Electrical Synapses Research Group, National Brain Research Program (NAP 2.0), Hungarian Academy of Sciences, Budapest, Hungary
- Department of Experimental Zoology and Neurobiology, University of Pécs, Pécs, Hungary
| | - Márton Balogh
- János Szentágothai Research Centre, University of Pécs, Pécs, Hungary
- Retinal Electrical Synapses Research Group, National Brain Research Program (NAP 2.0), Hungarian Academy of Sciences, Budapest, Hungary
- Department of Experimental Zoology and Neurobiology, University of Pécs, Pécs, Hungary
| | - Ádám J. Tengölics
- János Szentágothai Research Centre, University of Pécs, Pécs, Hungary
- Retinal Electrical Synapses Research Group, National Brain Research Program (NAP 2.0), Hungarian Academy of Sciences, Budapest, Hungary
- Department of Experimental Zoology and Neurobiology, University of Pécs, Pécs, Hungary
| | - Alma Ganczer
- János Szentágothai Research Centre, University of Pécs, Pécs, Hungary
- Retinal Electrical Synapses Research Group, National Brain Research Program (NAP 2.0), Hungarian Academy of Sciences, Budapest, Hungary
- Department of Experimental Zoology and Neurobiology, University of Pécs, Pécs, Hungary
| | - Béla Völgyi
- János Szentágothai Research Centre, University of Pécs, Pécs, Hungary
- Retinal Electrical Synapses Research Group, National Brain Research Program (NAP 2.0), Hungarian Academy of Sciences, Budapest, Hungary
- Department of Experimental Zoology and Neurobiology, University of Pécs, Pécs, Hungary
- Medical School, University of Pécs, Pécs, Hungary
| | - Tamás Kovács-Öller
- János Szentágothai Research Centre, University of Pécs, Pécs, Hungary
- Retinal Electrical Synapses Research Group, National Brain Research Program (NAP 2.0), Hungarian Academy of Sciences, Budapest, Hungary
- Medical School, University of Pécs, Pécs, Hungary
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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Tengölics ÁJ, Szarka G, Ganczer A, Szabó-Meleg E, Nyitrai M, Kovács-Öller T, Völgyi B. Response Latency Tuning by Retinal Circuits Modulates Signal Efficiency. Sci Rep 2019; 9:15110. [PMID: 31641196 PMCID: PMC6806000 DOI: 10.1038/s41598-019-51756-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2019] [Accepted: 10/07/2019] [Indexed: 12/31/2022] Open
Abstract
In the visual system, retinal ganglion cells (RGCs) of various subtypes encode preprocessed photoreceptor signals into a spike output which is then transmitted towards the brain through parallel feature pathways. Spike timing determines how each feature signal contributes to the output of downstream neurons in visual brain centers, thereby influencing efficiency in visual perception. In this study, we demonstrate a marked population-wide variability in RGC response latency that is independent of trial-to-trial variability and recording approach. RGC response latencies to simple visual stimuli vary considerably in a heterogenous cell population but remain reliable when RGCs of a single subtype are compared. This subtype specificity, however, vanishes when the retinal circuitry is bypassed via direct RGC electrical stimulation. This suggests that latency is primarily determined by the signaling speed through retinal pathways that provide subtype specific inputs to RGCs. In addition, response latency is significantly altered when GABA inhibition or gap junction signaling is disturbed, which further supports the key role of retinal microcircuits in latency tuning. Finally, modulation of stimulus parameters affects individual RGC response delays considerably. Based on these findings, we hypothesize that retinal microcircuits fine-tune RGC response latency, which in turn determines the context-dependent weighing of each signal and its contribution to visual perception.
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Affiliation(s)
- Ádám Jonatán Tengölics
- MTA-PTE NAP-2 Retinal Electrical Synapses Research Group, Pécs, H-7624, Hungary.,János Szentágothai Research Centre, Pécs, H-7624, Hungary.,Department of Experimental Zoology and Neurobiology, University of Pécs, Pécs, H-7624, Hungary
| | - Gergely Szarka
- MTA-PTE NAP-2 Retinal Electrical Synapses Research Group, Pécs, H-7624, Hungary.,János Szentágothai Research Centre, Pécs, H-7624, Hungary.,Department of Experimental Zoology and Neurobiology, University of Pécs, Pécs, H-7624, Hungary
| | - Alma Ganczer
- MTA-PTE NAP-2 Retinal Electrical Synapses Research Group, Pécs, H-7624, Hungary.,János Szentágothai Research Centre, Pécs, H-7624, Hungary.,Department of Experimental Zoology and Neurobiology, University of Pécs, Pécs, H-7624, Hungary
| | - Edina Szabó-Meleg
- János Szentágothai Research Centre, Pécs, H-7624, Hungary.,Department of Biophysics, University of Pécs Medical School, Pécs, H-7624, Hungary.,Nuclear-Mitochondrial Interactions Research Group, Hungarian Academy of Sciences (MTA-PTE), Pécs, H-7624, Hungary
| | - Miklós Nyitrai
- János Szentágothai Research Centre, Pécs, H-7624, Hungary.,Department of Biophysics, University of Pécs Medical School, Pécs, H-7624, Hungary.,Nuclear-Mitochondrial Interactions Research Group, Hungarian Academy of Sciences (MTA-PTE), Pécs, H-7624, Hungary
| | - Tamás Kovács-Öller
- MTA-PTE NAP-2 Retinal Electrical Synapses Research Group, Pécs, H-7624, Hungary.,János Szentágothai Research Centre, Pécs, H-7624, Hungary.,Department of Experimental Zoology and Neurobiology, University of Pécs, Pécs, H-7624, Hungary
| | - Béla Völgyi
- MTA-PTE NAP-2 Retinal Electrical Synapses Research Group, Pécs, H-7624, Hungary. .,János Szentágothai Research Centre, Pécs, H-7624, Hungary. .,Department of Experimental Zoology and Neurobiology, University of Pécs, Pécs, H-7624, Hungary.
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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Ganczer A, Balogh M, Albert L, Debertin G, Kovács-Öller T, Völgyi B. Transiency of retinal ganglion cell action potential responses determined by PSTH time constant. PLoS One 2017; 12:e0183436. [PMID: 28898257 PMCID: PMC5595288 DOI: 10.1371/journal.pone.0183436] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2017] [Accepted: 08/03/2017] [Indexed: 11/18/2022] Open
Abstract
Retinal ganglion cells (RGC) have been described to react to light stimuli either by producing short bursts of spikes or by maintaining a longer, continuous train of action potentials. Fast, quickly decaying responses are considered to be transient in nature and encode information about movement and direction, while cell responses that show a slow, drawn-out response fall into the sustained category and are thought to be responsible for carrying information related to color and contrast. Multiple approaches have been introduced thus far to measure and determine response transiency. In this study, we adopted and slightly modified a method described by Zeck and Masland to characterize RGC response transiency values and compare them to those obtained by alternative methods. As the first step, RGC spike responses were elicited by light stimulation and peristimulus time histograms (PSTHs) were generated. PSTHs then were used to calculate the time constant (PSTHτ approach). We show that this method is comparable to or more reliable than alternative approaches to describe the temporal characteristics of RGC light responses. In addition, we also show that PSTHτ-s are compatible with time constants measured on RGC and/or bipolar cell graded potentials; thus they are suitable for studying signaling through parallel retinal pathways.
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Affiliation(s)
- Alma Ganczer
- MTA-PTE NAP B Retinal Electrical Synapses Research Group, Pécs, Hungary
- Department of Experimental Zoology and Neurobiology, University of Pécs, Pécs, Hungary
- János Szentágothai Research Center, University of Pécs, Pécs, Hungary
| | - Márton Balogh
- MTA-PTE NAP B Retinal Electrical Synapses Research Group, Pécs, Hungary
- Department of Experimental Zoology and Neurobiology, University of Pécs, Pécs, Hungary
- János Szentágothai Research Center, University of Pécs, Pécs, Hungary
| | - László Albert
- MTA-PTE NAP B Retinal Electrical Synapses Research Group, Pécs, Hungary
- Department of Experimental Zoology and Neurobiology, University of Pécs, Pécs, Hungary
- János Szentágothai Research Center, University of Pécs, Pécs, Hungary
| | - Gábor Debertin
- MTA-PTE NAP B Retinal Electrical Synapses Research Group, Pécs, Hungary
- Department of Experimental Zoology and Neurobiology, University of Pécs, Pécs, Hungary
- János Szentágothai Research Center, University of Pécs, Pécs, Hungary
| | - Tamás Kovács-Öller
- MTA-PTE NAP B Retinal Electrical Synapses Research Group, Pécs, Hungary
- Department of Experimental Zoology and Neurobiology, University of Pécs, Pécs, Hungary
- János Szentágothai Research Center, University of Pécs, Pécs, Hungary
| | - Béla Völgyi
- MTA-PTE NAP B Retinal Electrical Synapses Research Group, Pécs, Hungary
- Department of Experimental Zoology and Neurobiology, University of Pécs, Pécs, Hungary
- János Szentágothai Research Center, University of Pécs, Pécs, Hungary
- * E-mail: , (BV)
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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Szalai R, Ganczer A, Magyari L, Matyas P, Bene J, Melegh B. Interethnic differences of cytochrome P450 gene polymorphisms may influence outcome of taxane therapy in Roma and Hungarian populations. Drug Metab Pharmacokinet 2015; 30:453-6. [PMID: 26507668 DOI: 10.1016/j.dmpk.2015.08.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2015] [Revised: 07/24/2015] [Accepted: 08/03/2015] [Indexed: 11/18/2022]
Abstract
Taxanes are widely used microtubule-stabilizing chemotherapeutic agents in the treatment of cancers. Several cytochrome P450 gene variants have been proven to influence taxane metabolism and therapy. The purpose of this work was to determine the distribution of genetic variations of CYP1B1, CYP2C8 and CYP3A5 genes as the first report on taxane metabolizer cytochrome P450 gene polymorphisms in Roma and Hungarian populations. A total of 397 Roma and 412 Hungarian healthy subjects were genotyped for CYP1B1 c.4326C > G, CYP2C8 c.792C > G and CYP3A5 c.6986A > G variant alleles by PCR-RFLP assay and direct sequencing. We found significant differences in the frequencies of homozygous variant genotypes of CYP1B1 4326 GG (p = 0.002) and CYP3A5 6986 GG (p < 0.001) between Roma and Hungarian populations. Regarding minor allele frequencies, for CYP2C8 a significantly increased prevalence was found in 792G allele frequency in the Hungarian population compared to the Roma population (5.83% vs. 2.14%, p = 0.001). Our results can be used as possible predictive factors in population specific treatment algorithms to developing effective programs for a better outcome in patients treated with taxanes.
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Affiliation(s)
- Renata Szalai
- University of Pecs, Clinical Center, Department of Medical Genetics, H-7624 Pecs, Szigeti 12, Hungary; Janos Szentagothai Research Centre, Human Genetic and Pharmacogenomic Research Group, H-7624 Pecs, Ifjusag 20, Hungary
| | - Alma Ganczer
- University of Pecs, Clinical Center, Department of Medical Genetics, H-7624 Pecs, Szigeti 12, Hungary
| | - Lili Magyari
- University of Pecs, Clinical Center, Department of Medical Genetics, H-7624 Pecs, Szigeti 12, Hungary; Janos Szentagothai Research Centre, Human Genetic and Pharmacogenomic Research Group, H-7624 Pecs, Ifjusag 20, Hungary
| | - Petra Matyas
- University of Pecs, Clinical Center, Department of Medical Genetics, H-7624 Pecs, Szigeti 12, Hungary
| | - Judit Bene
- University of Pecs, Clinical Center, Department of Medical Genetics, H-7624 Pecs, Szigeti 12, Hungary
| | - Bela Melegh
- University of Pecs, Clinical Center, Department of Medical Genetics, H-7624 Pecs, Szigeti 12, Hungary; Janos Szentagothai Research Centre, Human Genetic and Pharmacogenomic Research Group, H-7624 Pecs, Ifjusag 20, Hungary.
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Nagy A, Sipeky C, Szalai R, Melegh BI, Matyas P, Ganczer A, Toth K, Melegh B. Marked differences in frequencies of statin therapy relevant SLCO1B1 variants and haplotypes between Roma and Hungarian populations. BMC Genet 2015; 16:108. [PMID: 26334733 PMCID: PMC4559300 DOI: 10.1186/s12863-015-0262-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2015] [Accepted: 08/12/2015] [Indexed: 01/26/2023] Open
Abstract
Background SLCO1B1 polymorphisms are relevant in statin pharmacokinetics. Aim of this study was to investigate the genetic variability and haplotype profile of SLCO1B1 polymorphisms in Roma and Hungarian populations. Genotypes of 470 Roma and 442 Hungarian subjects for c.388A > G, c.521T > C and c.1498-1331T > C polymorphisms were determined by PCR-RFLP assay. Using these SNPs eight different haplotypes could be differentiated. Results Differences were found between Roma and Hungarians in SLCO1B1 388AA (24.5 vs. 45.5 %), GG (33.4 vs. 17.9 %) genotypes, AG + GG (75.5 vs. 54.5 %) carriers, in G allele frequency (0.545 vs. 0.362), respectively (p < 0.001). The most common SLCO1B1 haplotype was the ht8 (GTT) both in Roma (43.6 %) and in Hungarian (59.1 %) samples. The ht6 (GCT) was not present in Roma population samples Haplotype analyses showed striking differences between the Roma and Hungarian samples in ht4 (ATT, 37.2 % vs 20.8 %), ht5 (GCC, 1.15 % vs. 3.62 %) and ht8 (GTT, 43.6 % vs. 59.1 %) haplotypes (p < 0.01), respectively. Linkage disequilibrium analysis showed that the studied variants are in different linkage disequilibrium patterns depending on the ethnic origin. Conclusions Similarly to Caucasians the 388G is the minor allele in Hungarians, however, in Roma the 388A was found to be the minor allele contrary to Indians (India). The minor allele frequency of 521T > C and 1498-1331T > C SNPs are almost three times higher in Romas than in Indians (Singapore and Gujarati, respectively). Observed allele frequency for 1498-1331T > C polymorphism reflects the measured average European rates in Hungarians. The results can be applied in population specific treatment algorithms when developing effective programs for statin therapy.
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Affiliation(s)
- Agnes Nagy
- 1st Department of Internal Medicine, University of Pecs, Pecs, Hungary.
| | - Csilla Sipeky
- Department of Medical Genetics, Clinical Centre, University of Pecs, Szigeti 12, H-7624, Pecs, Hungary. .,Janos Szentagothai Research Centre, Human Genetic and Pharmacogenomic Research Group, University of Pecs, Pecs, Hungary.
| | - Renata Szalai
- Department of Medical Genetics, Clinical Centre, University of Pecs, Szigeti 12, H-7624, Pecs, Hungary. .,Janos Szentagothai Research Centre, Human Genetic and Pharmacogenomic Research Group, University of Pecs, Pecs, Hungary.
| | - Bela Imre Melegh
- Department of Medical Genetics, Clinical Centre, University of Pecs, Szigeti 12, H-7624, Pecs, Hungary.
| | - Petra Matyas
- Department of Medical Genetics, Clinical Centre, University of Pecs, Szigeti 12, H-7624, Pecs, Hungary.
| | - Alma Ganczer
- Department of Medical Genetics, Clinical Centre, University of Pecs, Szigeti 12, H-7624, Pecs, Hungary.
| | - Kalman Toth
- 1st Department of Internal Medicine, University of Pecs, Pecs, Hungary.
| | - Bela Melegh
- Department of Medical Genetics, Clinical Centre, University of Pecs, Szigeti 12, H-7624, Pecs, Hungary. .,Janos Szentagothai Research Centre, Human Genetic and Pharmacogenomic Research Group, University of Pecs, Pecs, Hungary.
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Sipeky C, Weber A, Melegh BI, Matyas P, Janicsek I, Szalai R, Szabo I, Varnai R, Tarlos G, Ganczer A, Melegh B. Interethnic variability of CYP4F2 (V433M) in admixed population of Roma and Hungarians. Environ Toxicol Pharmacol 2015; 40:280-283. [PMID: 26176903 DOI: 10.1016/j.etap.2015.05.008] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/06/2015] [Revised: 05/13/2015] [Accepted: 05/16/2015] [Indexed: 06/04/2023]
Abstract
AIMS Pharmacogenetic based dosing recommendations are provided in FDA-approved warfarin label for Caucasians. Evidence of notable difference in dosing algorithms of under-represented populations forced us to explore the genetic variability of CYP4F2 gene in Roma and Hungarian populations. PATIENTS AND METHODS 484 Roma, 493 Hungarian untreated subjects were genotyped for the CYP4F2*3 (rs2108622) variant by PCR-RFLP assay. RESULTS AND DISCUSSION We firstly report, that frequencies of the CYP4F2 rs2108622 GG, GA, AA genotypes and A allele in the Roma population were 46.5%, 42.6%, 10.9% and 32.2%; in Hungarians 50.1%, 42.2%, 7.7% and 22.8%, respectively. Bearing of two minor alleles of CYP4F2 missense variant (AA genotype) modestly explains inter-ethnic differences of studied populations (p<0.08). CYP4F2*3 (V433M) risk allele frequency of Roma (0.32) was in higher range, and of Hungarians (0.23) in lower range, as compared with other world populations. CONCLUSIONS Roma have an elevated chance for higher mean warfarin dose, besides a decreased risk of major bleeding events in long-term warfarin use.
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Affiliation(s)
- Csilla Sipeky
- University of Pecs, Clinical Centre, Department of Medical Genetics, Szigeti 12, H-7624 Pecs, Hungary; Human Genetic and Pharmacogenetic Research Group, Janos Szentagothai Research Centre, Ifjusag 20, H-7624 Pecs, Hungary.
| | - Agnes Weber
- B.A.Z County Hospital and University Teaching Hospital, Szentpeteri Gate 72-76, H-3526 Miskolc, Hungary
| | - Bela I Melegh
- University of Pecs, Clinical Centre, Department of Medical Genetics, Szigeti 12, H-7624 Pecs, Hungary
| | - Petra Matyas
- University of Pecs, Clinical Centre, Department of Medical Genetics, Szigeti 12, H-7624 Pecs, Hungary
| | - Ingrid Janicsek
- University of Pecs, Clinical Centre, Department of Medical Genetics, Szigeti 12, H-7624 Pecs, Hungary
| | - Renata Szalai
- University of Pecs, Clinical Centre, Department of Medical Genetics, Szigeti 12, H-7624 Pecs, Hungary; Human Genetic and Pharmacogenetic Research Group, Janos Szentagothai Research Centre, Ifjusag 20, H-7624 Pecs, Hungary
| | - Istvan Szabo
- University of Pecs, Clinical Centre, Department of Medical Genetics, Szigeti 12, H-7624 Pecs, Hungary
| | - Reka Varnai
- University of Pecs, Institute of Family Medicine, Akac str. 1, H-7632 Pecs, Hungary
| | - Greta Tarlos
- University of Pecs, Clinical Centre, Department of Medical Genetics, Szigeti 12, H-7624 Pecs, Hungary
| | - Alma Ganczer
- University of Pecs, Clinical Centre, Department of Medical Genetics, Szigeti 12, H-7624 Pecs, Hungary
| | - Bela Melegh
- University of Pecs, Clinical Centre, Department of Medical Genetics, Szigeti 12, H-7624 Pecs, Hungary; Human Genetic and Pharmacogenetic Research Group, Janos Szentagothai Research Centre, Ifjusag 20, H-7624 Pecs, Hungary
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Sipeky C, Matyas P, Melegh M, Janicsek I, Szalai R, Szabo I, Varnai R, Tarlos G, Ganczer A, Melegh B. Lower carrier rate of GJB2 W24X ancestral Indian mutation in Roma samples from Hungary: implication for public health intervention. Mol Biol Rep 2014; 41:6105-10. [PMID: 24969484 DOI: 10.1007/s11033-014-3488-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2013] [Accepted: 06/17/2014] [Indexed: 11/29/2022]
Abstract
The purpose of this work was to characterise the W24X mutation of the GJB2 gene in order to provide more representative and geographicaly relevant carrier rates of healthy Roma subisolates and the Hungarian population. 493 Roma and 498 Hungarian healthy subjects were genotyped for the GJB2 c.71G>A (rs104894396, W24X) mutation by PCR-RFLP assay and direct sequencing. This is the first report on GJB2 W24X mutation in geographically subisolated Roma population of Hungary compared to local Hungarians. Comparing the genotype and allele frequencies of GJB2 rs104894396 mutation, significant difference was found in GG (98.4 vs. 99.8 %), GA (1.62 vs. 0.20 %) genotypes and A (0.8 vs. 0.1 %) allele between the Roma and Hungarian populations, respectively (p < 0.02). None of the subjects of Roma and Hungarian samples carried the GJB2 W24X AA genotype. Considerable result of our study, that the proportion of GJB2 W24X GA heterozygotes and the A allele frequency was eight times higher in Roma than in Hungarians. Considering the results, the mutant allele frequency both in Roma (0.8 %) and in Hungarian (0.1 %) populations is lower than expected from previous results, likely reflecting local differentiated subisolates of these populations and a suspected lower risk for GJB2 mutation related deafness. However, the significant difference in GJB2 W24X carrier rates between the Roma and Hungarians may initiate individual diagnostic investigations and effective public health interventions.
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Affiliation(s)
- Csilla Sipeky
- Department of Medical Genetics, Clinical Centre, University of Pecs, Szigeti 12, Pecs, 7624, Hungary,
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