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Tian Q, Tong P, Chen G, Deng M, Cai T, Tian R, Zhang Z, Xia K, Hu Z. GLRA2 gene mutations cause high myopia in humans and mice. J Med Genet 2023; 60:193-203. [PMID: 35396272 PMCID: PMC9887403 DOI: 10.1136/jmedgenet-2022-108425] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2022] [Accepted: 03/16/2022] [Indexed: 02/03/2023]
Abstract
BACKGROUND High myopia (HM) is a leading cause of blindness that has a strong genetic predisposition. However, its genetic and pathogenic mechanisms remain largely unknown. Thus, this study aims to determine the genetic profile of individuals from two large Chinese families with HM and 200 patients with familial/sporadic HM. We also explored the pathogenic mechanism of HM using HEK293 cells and a mouse model. METHODS The participants underwent genome-wide linkage analysis and exome sequencing. Visual acuity, electroretinogram response, refractive error, optical parameters and retinal rod cell genesis were measured in knockout mice. Immunofluorescent staining, biotin-labelled membrane protein isolation and electrophysiological characterisation were conducted in cells transfected with overexpression plasmids. RESULTS A novel HM locus on Xp22.2-p11.4 was identified. Variant c.539C>T (p.Pro180Leu) in GLRA2 gene was co-segregated with HM in the two families. Another variant, c.458G>A (p.Arg153Gln), was identified in a sporadic sample. The Glra2 knockout mice showed myopia-related phenotypes, decreased electroretinogram responses and impaired retinal rod cell genesis. Variants c.458G>A and c.539C>T altered the localisation of GlyRα2 on the cell membrane and decreased agonist sensitivity. CONCLUSION GLRA2 was identified as a novel HM-causing gene. Its variants would cause HM through altered visual experience by impairing photoperception and visual transmission.
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Affiliation(s)
- Qi Tian
- Center for Medical Genetics, School of Life Sciences, Central South University, Changsha, Hunan, People's Republic of China,Hunan Key Laboratory of Medical Genetics, School of Life Sciences, Central South University, Changsha, Hunan, People's Republic of China,Hunan Key Laboratory of Animal Models for Human Disease, School of Life Sciences, Central South University, Changsha, Hunan, People's Republic of China
| | - Ping Tong
- Department of Ophthalmology, The Second Xiangya Hospital, Central South University, Changsha, Hunan, People's Republic of China
| | - Gong Chen
- Hunan Key Laboratory of Medical Genetics, School of Life Sciences, Central South University, Changsha, Hunan, People's Republic of China,Hunan Key Laboratory of Animal Models for Human Disease, School of Life Sciences, Central South University, Changsha, Hunan, People's Republic of China,Hunan Province Key Laboratory of Basic and Applied Hematology, School of Life Sciences, Central South University, Changsha, Hunan, People's Republic of China,Department of Biochemistry and Molecular Biology, School of Life Sciences, Central South University, Changsha, Hunan, People's Republic of China
| | - Meichun Deng
- Hunan Key Laboratory of Medical Genetics, School of Life Sciences, Central South University, Changsha, Hunan, People's Republic of China,Hunan Key Laboratory of Animal Models for Human Disease, School of Life Sciences, Central South University, Changsha, Hunan, People's Republic of China,Hunan Province Key Laboratory of Basic and Applied Hematology, School of Life Sciences, Central South University, Changsha, Hunan, People's Republic of China,Department of Biochemistry and Molecular Biology, School of Life Sciences, Central South University, Changsha, Hunan, People's Republic of China
| | - Tian'e Cai
- Reproductive Center, Sanya Central Hospital, Sanya, Hainan, People's Republic of China
| | - Runyi Tian
- Center for Medical Genetics, School of Life Sciences, Central South University, Changsha, Hunan, People's Republic of China,Hunan Key Laboratory of Medical Genetics, School of Life Sciences, Central South University, Changsha, Hunan, People's Republic of China,Hunan Key Laboratory of Animal Models for Human Disease, School of Life Sciences, Central South University, Changsha, Hunan, People's Republic of China
| | - Zimin Zhang
- Center for Medical Genetics, School of Life Sciences, Central South University, Changsha, Hunan, People's Republic of China,Hunan Key Laboratory of Medical Genetics, School of Life Sciences, Central South University, Changsha, Hunan, People's Republic of China,Hunan Key Laboratory of Animal Models for Human Disease, School of Life Sciences, Central South University, Changsha, Hunan, People's Republic of China
| | - Kun Xia
- Center for Medical Genetics, School of Life Sciences, Central South University, Changsha, Hunan, People's Republic of China .,Hunan Key Laboratory of Medical Genetics, School of Life Sciences, Central South University, Changsha, Hunan, People's Republic of China.,Hunan Key Laboratory of Animal Models for Human Disease, School of Life Sciences, Central South University, Changsha, Hunan, People's Republic of China
| | - Zhengmao Hu
- Center for Medical Genetics, School of Life Sciences, Central South University, Changsha, Hunan, People's Republic of China .,Hunan Key Laboratory of Medical Genetics, School of Life Sciences, Central South University, Changsha, Hunan, People's Republic of China.,Hunan Key Laboratory of Animal Models for Human Disease, School of Life Sciences, Central South University, Changsha, Hunan, People's Republic of China
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Kim S, Roh H, Im M. Artificial Visual Information Produced by Retinal Prostheses. Front Cell Neurosci 2022; 16:911754. [PMID: 35734216 PMCID: PMC9208577 DOI: 10.3389/fncel.2022.911754] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2022] [Accepted: 05/18/2022] [Indexed: 11/18/2022] Open
Abstract
Numerous retinal prosthetic systems have demonstrated somewhat useful vision can be restored to individuals who had lost their sight due to outer retinal degenerative diseases. Earlier prosthetic studies have mostly focused on the confinement of electrical stimulation for improved spatial resolution and/or the biased stimulation of specific retinal ganglion cell (RGC) types for selective activation of retinal ON/OFF pathway for enhanced visual percepts. To better replicate normal vision, it would be also crucial to consider information transmission by spiking activities arising in the RGC population since an incredible amount of visual information is transferred from the eye to the brain. In previous studies, however, it has not been well explored how much artificial visual information is created in response to electrical stimuli delivered by microelectrodes. In the present work, we discuss the importance of the neural information for high-quality artificial vision. First, we summarize the previous literatures which have computed information transmission rates from spiking activities of RGCs in response to visual stimuli. Second, we exemplify a couple of studies which computed the neural information from electrically evoked responses. Third, we briefly introduce how information rates can be computed in the representative two ways - direct method and reconstruction method. Fourth, we introduce in silico approaches modeling artificial retinal neural networks to explore the relationship between amount of information and the spiking patterns. Lastly, we conclude our review with clinical implications to emphasize the necessity of considering visual information transmission for further improvement of retinal prosthetics.
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Affiliation(s)
- Sein Kim
- Brain Science Institute, Korea Institute of Science and Technology, Seoul, South Korea
| | - Hyeonhee Roh
- Brain Science Institute, Korea Institute of Science and Technology, Seoul, South Korea
- School of Electrical Engineering, College of Engineering, Korea University, Seoul, South Korea
| | - Maesoon Im
- Brain Science Institute, Korea Institute of Science and Technology, Seoul, South Korea
- Division of Bio-Medical Science & Technology, KIST School, University of Science and Technology, Seoul, South Korea
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3
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van der Sande E, Haarman AEG, Quint WH, Tadema KCD, Meester-Smoor MA, Kamermans M, De Zeeuw CI, Klaver CCW, Winkelman BHJ, Iglesias AI. The Role of GJD2(Cx36) in Refractive Error Development. Invest Ophthalmol Vis Sci 2022; 63:5. [PMID: 35262731 PMCID: PMC8934558 DOI: 10.1167/iovs.63.3.5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2021] [Accepted: 02/16/2022] [Indexed: 02/06/2023] Open
Abstract
Refractive errors are common eye disorders characterized by a mismatch between the focal power of the eye and its axial length. An increased axial length is a common cause of the refractive error myopia (nearsightedness). The substantial increase in myopia prevalence over the last decades has raised public health concerns because myopia can lead to severe ocular complications later in life. Genomewide association studies (GWAS) have made considerable contributions to the understanding of the genetic architecture of refractive errors. Among the hundreds of genetic variants identified, common variants near the gap junction delta-2 (GJD2) gene have consistently been reported as one of the top hits. GJD2 encodes the connexin 36 (Cx36) protein, which forms gap junction channels and is highly expressed in the neural retina. In this review, we provide current evidence that links GJD2(Cx36) to the development of myopia. We summarize the gap junctional communication in the eye and the specific role of GJD2(Cx36) in retinal processing of visual signals. Finally, we discuss the pathways involving dopamine and gap junction phosphorylation and coupling as potential mechanisms that may explain the role of GJD2(Cx36) in refractive error development.
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Affiliation(s)
- Emilie van der Sande
- Department of Ophthalmology, Erasmus Medical Center, Rotterdam, The Netherlands
- Department of Epidemiology, Erasmus Medical Center, Rotterdam, The Netherlands
- Netherlands Institute for Neuroscience (NIN), Royal Dutch Academy of Art & Science (KNAW), Amsterdam, The Netherlands
| | - Annechien E. G. Haarman
- Department of Ophthalmology, Erasmus Medical Center, Rotterdam, The Netherlands
- Department of Epidemiology, Erasmus Medical Center, Rotterdam, The Netherlands
| | - Wim H. Quint
- Department of Ophthalmology, Erasmus Medical Center, Rotterdam, The Netherlands
- Department of Epidemiology, Erasmus Medical Center, Rotterdam, The Netherlands
| | - Kirke C. D. Tadema
- Department of Ophthalmology, Erasmus Medical Center, Rotterdam, The Netherlands
- Department of Epidemiology, Erasmus Medical Center, Rotterdam, The Netherlands
| | - Magda A. Meester-Smoor
- Department of Ophthalmology, Erasmus Medical Center, Rotterdam, The Netherlands
- Department of Epidemiology, Erasmus Medical Center, Rotterdam, The Netherlands
| | - Maarten Kamermans
- Netherlands Institute for Neuroscience (NIN), Royal Dutch Academy of Art & Science (KNAW), Amsterdam, The Netherlands
- Department of Biomedical Physics and Biomedical Photonics, Amsterdam University Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - Chris I. De Zeeuw
- Netherlands Institute for Neuroscience (NIN), Royal Dutch Academy of Art & Science (KNAW), Amsterdam, The Netherlands
- Department of Neuroscience, Erasmus Medical Center, Rotterdam, The Netherlands
| | - Caroline C. W. Klaver
- Department of Ophthalmology, Erasmus Medical Center, Rotterdam, The Netherlands
- Department of Epidemiology, Erasmus Medical Center, Rotterdam, The Netherlands
- Department of Ophthalmology, Radboud University Medical Center, Nijmegen, The Netherlands
- Institute of Molecular and Clinical Ophthalmology, Basel, Switzerland
| | - Beerend H. J. Winkelman
- Department of Ophthalmology, Erasmus Medical Center, Rotterdam, The Netherlands
- Department of Epidemiology, Erasmus Medical Center, Rotterdam, The Netherlands
- Netherlands Institute for Neuroscience (NIN), Royal Dutch Academy of Art & Science (KNAW), Amsterdam, The Netherlands
- Department of Neuroscience, Erasmus Medical Center, Rotterdam, The Netherlands
| | - Adriana I. Iglesias
- Department of Ophthalmology, Erasmus Medical Center, Rotterdam, The Netherlands
- Department of Clinical Genetics, Erasmus Medical Center, Rotterdam, The Netherlands
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Glycine Release Is Potentiated by cAMP via EPAC2 and Ca 2+ Stores in a Retinal Interneuron. J Neurosci 2021; 41:9503-9520. [PMID: 34620721 PMCID: PMC8612479 DOI: 10.1523/jneurosci.0670-21.2021] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Revised: 09/28/2021] [Accepted: 09/30/2021] [Indexed: 11/21/2022] Open
Abstract
Neuromodulation via the intracellular second messenger cAMP is ubiquitous at presynaptic nerve terminals. This modulation of synaptic transmission allows exocytosis to adapt to stimulus levels and reliably encode information. The AII amacrine cell (AII-AC) is a central hub for signal processing in the mammalian retina. The main apical dendrite of the AII-AC is connected to several lobular appendages that release glycine onto OFF cone bipolar cells and ganglion cells. However, the influence of cAMP on glycine release is not well understood. Using membrane capacitance measurements from mouse AII-ACs to directly measure exocytosis, we observe that intracellular dialysis of 1 mm cAMP enhances exocytosis without affecting the L-type Ca2+ current. Responses to depolarizing pulses of various durations show that the size of the readily releasable pool of vesicles nearly doubles with cAMP, while paired-pulse depression experiments suggest that release probability does not change. Specific agonists and antagonists for exchange protein activated by cAMP 2 (EPAC2) revealed that the cAMP-induced enhancement of exocytosis requires EPAC2 activation. Furthermore, intact Ca2+ stores were also necessary for the cAMP potentiation of exocytosis. Postsynaptic recordings from OFF cone bipolar cells showed that increasing cAMP with forskolin potentiated the frequency of glycinergic spontaneous IPSCs. We propose that cAMP elevations in the AII-AC lead to a robust enhancement of glycine release through an EPAC2 and Ca2+ store signaling pathway. Our results thus contribute to a better understanding of how AII-AC crossover inhibitory circuits adapt to changes in ambient luminance.SIGNIFICANCE STATEMENT The mammalian retina operates over a wide dynamic range of light intensities and contrast levels. To optimize the signal-to-noise ratio of processed visual information, both excitatory and inhibitory synapses within the retina must modulate their gain in synaptic transmission to adapt to different levels of ambient light. Here we show that increases of cAMP concentration within AII amacrine cells produce enhanced exocytosis from these glycinergic interneurons. Therefore, we propose that light-sensitive neuromodulators may change the output of glycine release from AII amacrine cells. This novel mechanism may fine-tune the amount of tonic and phasic synaptic inhibition received by bipolar cell terminals and, consequently, the spiking patterns that ganglion cells send to the upstream visual areas of the brain.
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Liu X, Li H, Wang Y, Lei T, Wang J, Spillmann L, Andolina IM, Wang W. From Receptive to Perceptive Fields: Size-Dependent Asymmetries in Both Negative Afterimages and Subcortical On and Off Post-Stimulus Responses. J Neurosci 2021; 41:7813-7830. [PMID: 34326144 PMCID: PMC8445057 DOI: 10.1523/jneurosci.0300-21.2021] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Revised: 07/11/2021] [Accepted: 07/13/2021] [Indexed: 11/21/2022] Open
Abstract
Negative afterimages are perceptual phenomena that occur after physical stimuli disappear from sight. Their origin is linked to transient post-stimulus responses of visual neurons. The receptive fields (RFs) of these subcortical ON- and OFF-center neurons exhibit antagonistic interactions between central and surrounding visual space, resulting in selectivity for stimulus polarity and size. These two features are closely intertwined, yet their relationship to negative afterimage perception remains unknown. Here we tested whether size differentially affects the perception of bright and dark negative afterimages in humans of both sexes, and how this correlates with neural mechanisms in subcortical ON and OFF cells. Psychophysically, we found a size-dependent asymmetry whereby dark disks produce stronger and longer-lasting negative afterimages than bright disks of equal contrast at sizes >0.8°. Neurophysiological recordings from retinal and relay cells in female cat dorsal lateral geniculate nucleus showed that subcortical ON cells exhibited stronger sustained post-stimulus responses to dark disks, than OFF cells to bright disks, at sizes >1°. These sizes agree with the emergence of center-surround antagonism, revealing stronger suppression to opposite-polarity stimuli for OFF versus ON cells, particularly in dorsal lateral geniculate nucleus. Using a network-based retino-geniculate model, we confirmed stronger antagonism and temporal transience for OFF-cell post-stimulus rebound responses. A V1 population model demonstrated that both strength and duration asymmetries can be propagated to downstream cortical areas. Our results demonstrate how size-dependent antagonism impacts both the neuronal post-stimulus response and the resulting afterimage percepts, thereby supporting the idea of perceptual RFs reflecting the underlying neuronal RF organization of single cells.SIGNIFICANCE STATEMENT Visual illusions occur when sensory inputs and perceptual outcomes do not match, and provide a valuable tool to understand transformations from neural to perceptual responses. A classic example are negative afterimages that remain visible after a stimulus is removed from view. Such perceptions are linked to responses in early visual neurons, yet the details remain poorly understood. Combining human psychophysics, neurophysiological recordings in cats and retino-thalamo-cortical computational modeling, our study reveals how stimulus size and the receptive-field structure of subcortical ON and OFF cells contributes to the parallel asymmetries between neural and perceptual responses to bright versus dark afterimages. Thus, this work provides a deeper link from the underlying neural mechanisms to the resultant perceptual outcomes.
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Affiliation(s)
- Xu Liu
- Institute of Neuroscience, Center for Excellence in Brain Science and Intelligence Technology, State Key Laboratory of Neuroscience, Key Laboratory of Primate Neurobiology, Chinese Academy of Sciences, Shanghai, 200031, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Hui Li
- Institute of Neuroscience, Center for Excellence in Brain Science and Intelligence Technology, State Key Laboratory of Neuroscience, Key Laboratory of Primate Neurobiology, Chinese Academy of Sciences, Shanghai, 200031, China
| | - Ye Wang
- State Key Laboratory of Media Convergence and Communication, Neuroscience and Intelligent Media Institute, Communication University of China, Beijing, 100024, China
| | - Tianhao Lei
- Institute of Neuroscience, Center for Excellence in Brain Science and Intelligence Technology, State Key Laboratory of Neuroscience, Key Laboratory of Primate Neurobiology, Chinese Academy of Sciences, Shanghai, 200031, China
| | - Jijun Wang
- Shanghai Mental Health Center, Shanghai Jiaotong University School of Medicine, Shanghai Key Laboratory of Psychotic Disorders, Shanghai, 200030, China
| | - Lothar Spillmann
- Department of Neurology, University of Freiburg, Freiburg, 79085, Germany
| | - Ian Max Andolina
- Institute of Neuroscience, Center for Excellence in Brain Science and Intelligence Technology, State Key Laboratory of Neuroscience, Key Laboratory of Primate Neurobiology, Chinese Academy of Sciences, Shanghai, 200031, China
- Shanghai Center for Brain and Brain-inspired Intelligence Technology, Shanghai, 200031, China
| | - Wei Wang
- Institute of Neuroscience, Center for Excellence in Brain Science and Intelligence Technology, State Key Laboratory of Neuroscience, Key Laboratory of Primate Neurobiology, Chinese Academy of Sciences, Shanghai, 200031, China
- Shanghai Center for Brain and Brain-inspired Intelligence Technology, Shanghai, 200031, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
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6
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Risner ML, McGrady NR, Boal AM, Pasini S, Calkins DJ. TRPV1 Supports Axogenic Enhanced Excitability in Response to Neurodegenerative Stress. Front Cell Neurosci 2021; 14:603419. [PMID: 33505248 PMCID: PMC7829306 DOI: 10.3389/fncel.2020.603419] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2020] [Accepted: 12/15/2020] [Indexed: 01/24/2023] Open
Abstract
Early progression in neurodegenerative disease involves challenges to homeostatic processes, including those controlling axonal excitability and dendritic organization. In glaucoma, the leading cause of irreversible blindness, stress from intraocular pressure (IOP) causes degeneration of retinal ganglion cells (RGC) and their axons which comprise the optic nerve. Previously, we discovered that early progression induces axogenic, voltage-gated enhanced excitability of RGCs, even as dendritic complexity in the retina reduces. Here, we investigate a possible contribution of the transient receptor potential vanilloid type 1 (TRPV1) channel to enhanced excitability, given its role in modulating excitation in other neural systems. We find that genetic deletion of Trpv1 (Trpv1−/−) influences excitability differently for RGCs firing continuously to light onset (αON-Sustained) vs. light offset (αOFF-Sustained). Deletion drives excitability in opposing directions so that Trpv1−/− RGC responses with elevated IOP equalize to that of wild-type (WT) RGCs without elevated IOP. Depolarizing current injections in the absence of light-driven presynaptic excitation to directly modulate voltage-gated channels mirrored these changes, while inhibiting voltage-gated sodium channels and isolating retinal excitatory postsynaptic currents abolished both the differences in light-driven activity between WT and Trpv1−/− RGCs and changes in response due to IOP elevation. Together, these results support a voltage-dependent, axogenic influence of Trpv1−/− with elevated IOP. Finally, Trpv1−/− slowed the loss of dendritic complexity with elevated IOP, opposite its effect on axon degeneration, supporting the idea that axonal and dendritic degeneration follows distinctive programs even at the level of membrane excitability.
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Affiliation(s)
- Michael L Risner
- Department of Ophthalmology and Visual Sciences, Vanderbilt Eye Institute, Vanderbilt University Medical Center, Nashville, TN, United States
| | - Nolan R McGrady
- Department of Ophthalmology and Visual Sciences, Vanderbilt Eye Institute, Vanderbilt University Medical Center, Nashville, TN, United States
| | - Andrew M Boal
- Department of Ophthalmology and Visual Sciences, Vanderbilt Eye Institute, Vanderbilt University Medical Center, Nashville, TN, United States
| | - Silvia Pasini
- Department of Ophthalmology and Visual Sciences, Vanderbilt Eye Institute, Vanderbilt University Medical Center, Nashville, TN, United States
| | - David J Calkins
- Department of Ophthalmology and Visual Sciences, Vanderbilt Eye Institute, Vanderbilt University Medical Center, Nashville, TN, United States
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Lee JI, Im M. Optimal Electric Stimulus Amplitude Improves the Selectivity Between Responses of ON Versus OFF Types of Retinal Ganglion Cells. IEEE Trans Neural Syst Rehabil Eng 2019; 27:2015-2024. [PMID: 31484127 DOI: 10.1109/tnsre.2019.2939012] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Outer retinal degenerative diseases destroy photoreceptors primarily in the retina, resulting in a profound vision loss. Fortunately, surviving retinal neurons can be electrically stimulated using retinal prostheses to re-transmit visual information. Although retinal prostheses are promising for sight restoration, the best performance is still sub-optimal. For the enhanced performance, it is critical to optimize stimulation parameters. This study explored how stimulus charge and current amplitude alters responses of retinal ganglion cells (RGCs). From the isolated mouse retina, spiking activities of alpha ON, OFF sustained, and OFF transient RGCs were recorded in response to epiretinally-delivered cathodal current pulses ranging from -10 to [Formula: see text]. We have found that intermediate current amplitudes (-30 and [Formula: see text]) maximize the response ratio of ON over OFF types. Also, the ON/OFF response ratio was always bigger for 10-ms-long than 5-ms-long stimuli. It was because, by the longer pulses, ON RGC responses were always significantly enhanced ( ) while OFF RGC responses were minimally changed ( ). Given the earlier work reporting electrically-elicited responses are more natural in ON than OFF RGCs, the present study suggests effect strategies of more selective activation of ON RGCs for improved efficacy of retinal implant.
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Yang GY, Liu FY, Li X, Zhu QR, Chen BJ, Liu LQ. Decreased expression of gap junction delta-2 (GJD2) messenger RNA and connexin 36 protein in form-deprivation myopia of guinea pigs. Chin Med J (Engl) 2019; 132:1700-1705. [PMID: 31283648 PMCID: PMC6759107 DOI: 10.1097/cm9.0000000000000319] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2018] [Indexed: 02/05/2023] Open
Abstract
BACKGROUND More than ten genome-wide association studies have identified the significant association between the gap junction delta-2 (GJD2) gene and myopia. However, no functional studies have been performed to confirm that this gene is correlated with myopia. This study aimed to observe how this gene changed in mRNA and protein level in the form-deprivation myopia (FDM) animal model. METHODS Four-week-old guinea pigs were randomly divided into two groups: control and FDM groups (n = 12 for each group). The right eyes of the FDM group were covered with opaque hemispherical plastic lenses for 3 weeks. For all the animals, refractive status, axial length (AL), and corneal radius of curvature were measured at baseline and 3 weeks later by streak retinoscope, A-scan ultrasonography, and keratometer, respectively. Retinal GJD2 mRNA expression and connexin 36 (Cx36) levels in FDM and control groups were measured by quantitative real-time PCR and Western blot analyses, respectively. Those results were compared using independent t test, Mann-Whitney U test, or paired t test. A significance level of P < 0.05 was used. RESULTS Three weeks later, the FDM group (form-deprived eyes) showed about a myopic shift of approximately -6.75 (-7.94 to -6.31) D, while the control group remained hyperopic with only a shift of -0.50 (-0.75 to 0.25) D (Z = -3.38, P < 0.01). The AL increased by 0.74 (0.61-0.76) and 0.10 (0.05-0.21) mm in FDM and control groups, respectively (Z = -3.37, P < 0.01). The relative mRNA expression of GJD2 in the FDM group decreased 31.58% more than the control group (t = 11.44, P < 0.01). The relative protein expression of CX36 on the retina was lowered by 37.72% in form-deprivation eyes as compared to the controls (t = 17.74, P < 0.01). CONCLUSION Both the mRNA expression of GJD2 and Cx36 protein amount were significantly decreased in the retina of FDM guinea pigs. This indicates that Cx36 is involved in FDM development, providing compensating evidence for the results obtained from genome-wide association studies.
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Affiliation(s)
- Guo-Yuan Yang
- Department of Opthalmology, West China Hospital, Sichuan University, Chengdu, Sichuan 610041, China
| | - Feng-Yang Liu
- Department of Opthalmology, West China Hospital, Sichuan University, Chengdu, Sichuan 610041, China
- Department of Ophthalmology, First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, China
| | - Xia Li
- Department of Opthalmology, West China Hospital, Sichuan University, Chengdu, Sichuan 610041, China
| | - Qiu-Rong Zhu
- Department of Opthalmology, West China Hospital, Sichuan University, Chengdu, Sichuan 610041, China
| | - Bing-Jie Chen
- Department of Opthalmology, West China Hospital, Sichuan University, Chengdu, Sichuan 610041, China
| | - Long-Qian Liu
- Department of Opthalmology, West China Hospital, Sichuan University, Chengdu, Sichuan 610041, China
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Graydon CW, Lieberman EE, Rho N, Briggman KL, Singer JH, Diamond JS. Synaptic Transfer between Rod and Cone Pathways Mediated by AII Amacrine Cells in the Mouse Retina. Curr Biol 2018; 28:2739-2751.e3. [PMID: 30122532 PMCID: PMC6133723 DOI: 10.1016/j.cub.2018.06.063] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2018] [Revised: 05/24/2018] [Accepted: 06/22/2018] [Indexed: 02/03/2023]
Abstract
To understand computation in a neural circuit requires a complete synaptic connectivity map and a thorough grasp of the information-processing tasks performed by the circuit. Here, we dissect a microcircuit in the mouse retina in which scotopic visual information (i.e., single photon events, luminance, contrast) is encoded by rod bipolar cells (RBCs) and distributed to parallel ON and OFF cone bipolar cell (CBC) circuits via the AII amacrine cell, an inhibitory interneuron. Serial block-face electron microscopy (SBEM) reconstructions indicate that AIIs preferentially connect to one OFF CBC subtype (CBC2); paired whole-cell patch-clamp recordings demonstrate that, depending on the level of network activation, AIIs transmit distinct components of synaptic input from single RBCs to downstream ON and OFF CBCs. These findings highlight specific synaptic and circuit-level features that allow intermediate neurons (e.g., AIIs) within a microcircuit to filter and propagate information to downstream neurons.
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Affiliation(s)
- Cole W Graydon
- Synaptic Physiology Section, National Institute of Neurological Disorders and Stroke, NIH, Bethesda, MD 20892, USA
| | - Evan E Lieberman
- Department of Biology, University of Maryland, College Park, MD 20742, USA
| | - Nao Rho
- Department of Biology, University of Maryland, College Park, MD 20742, USA
| | - Kevin L Briggman
- Circuit Dynamics and Connectivity Unit, National Institute of Neurological Disorders and Stroke, NIH, Bethesda, MD 20892, USA
| | - Joshua H Singer
- Department of Biology, University of Maryland, College Park, MD 20742, USA
| | - Jeffrey S Diamond
- Synaptic Physiology Section, National Institute of Neurological Disorders and Stroke, NIH, Bethesda, MD 20892, USA.
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Mobarhan MH, Halnes G, Martínez-Cañada P, Hafting T, Fyhn M, Einevoll GT. Firing-rate based network modeling of the dLGN circuit: Effects of cortical feedback on spatiotemporal response properties of relay cells. PLoS Comput Biol 2018; 14:e1006156. [PMID: 29771919 PMCID: PMC5976212 DOI: 10.1371/journal.pcbi.1006156] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2018] [Revised: 05/30/2018] [Accepted: 04/23/2018] [Indexed: 12/01/2022] Open
Abstract
Visually evoked signals in the retina pass through the dorsal geniculate nucleus (dLGN) on the way to the visual cortex. This is however not a simple feedforward flow of information: there is a significant feedback from cortical cells back to both relay cells and interneurons in the dLGN. Despite four decades of experimental and theoretical studies, the functional role of this feedback is still debated. Here we use a firing-rate model, the extended difference-of-Gaussians (eDOG) model, to explore cortical feedback effects on visual responses of dLGN relay cells. For this model the responses are found by direct evaluation of two- or three-dimensional integrals allowing for fast and comprehensive studies of putative effects of different candidate organizations of the cortical feedback. Our analysis identifies a special mixed configuration of excitatory and inhibitory cortical feedback which seems to best account for available experimental data. This configuration consists of (i) a slow (long-delay) and spatially widespread inhibitory feedback, combined with (ii) a fast (short-delayed) and spatially narrow excitatory feedback, where (iii) the excitatory/inhibitory ON-ON connections are accompanied respectively by inhibitory/excitatory OFF-ON connections, i.e. following a phase-reversed arrangement. The recent development of optogenetic and pharmacogenetic methods has provided new tools for more precise manipulation and investigation of the thalamocortical circuit, in particular for mice. Such data will expectedly allow the eDOG model to be better constrained by data from specific animal model systems than has been possible until now for cat. We have therefore made the Python tool pyLGN which allows for easy adaptation of the eDOG model to new situations. On route from the retina to primary visual cortex, visually evoked signals have to pass through the dorsal lateral geniculate nucleus (dLGN). However, this is not an exclusive feedforward flow of information as feedback exists from neurons in the cortex back to both relay cells and interneurons in the dLGN. The functional role of this feedback remains mostly unresolved. Here, we use a firing-rate model, the extended difference-of-Gaussians (eDOG) model, to explore cortical feedback effects on visual responses of dLGN relay cells. Our analysis indicates that a particular mix of excitatory and inhibitory cortical feedback agrees best with available experimental observations. In this configuration ON-center relay cells receive both excitatory and (indirect) inhibitory feedback from ON-center cortical cells (ON-ON feedback) where the excitatory feedback is fast and spatially narrow while the inhibitory feedback is slow and spatially widespread. In addition to the ON-ON feedback, the connections are accompanied by OFF-ON connections following a so-called phase-reversed (push-pull) arrangement. To facilitate further applications of the model, we have made the Python tool pyLGN which allows for easy modification and evaluation of the a priori quite general eDOG model to new situations.
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Affiliation(s)
- Milad Hobbi Mobarhan
- Centre for Integrative Neuroplasticity, University of Oslo, Oslo, Norway
- Department of Biosciences, University of Oslo, Oslo, Norway
| | - Geir Halnes
- Centre for Integrative Neuroplasticity, University of Oslo, Oslo, Norway
- Department of Mathematical Sciences and Technology, Norwegian University of Life Sciences, Ås, Norway
| | - Pablo Martínez-Cañada
- Centro de Investigación en Tecnologías de la Información y de las Comunicaciones (CITIC), University of Granada, Granada, Spain
| | - Torkel Hafting
- Centre for Integrative Neuroplasticity, University of Oslo, Oslo, Norway
- Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway
| | - Marianne Fyhn
- Centre for Integrative Neuroplasticity, University of Oslo, Oslo, Norway
- Department of Biosciences, University of Oslo, Oslo, Norway
| | - Gaute T. Einevoll
- Centre for Integrative Neuroplasticity, University of Oslo, Oslo, Norway
- Department of Mathematical Sciences and Technology, Norwegian University of Life Sciences, Ås, Norway
- Department of Physics, University of Oslo, Oslo, Norway
- * E-mail:
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11
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Beaudoin DL, Kupershtok M, Demb JB. Selective synaptic connections in the retinal pathway for night vision. J Comp Neurol 2017; 527:117-132. [PMID: 28856684 DOI: 10.1002/cne.24313] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2017] [Revised: 08/15/2017] [Accepted: 08/16/2017] [Indexed: 12/15/2022]
Abstract
The mammalian retina encodes visual information in dim light using rod photoreceptors and a specialized circuit: rods→rod bipolar cells→AII amacrine cell. The AII amacrine cell uses sign-conserving electrical synapses to modulate ON cone bipolar cell terminals and sign-inverting chemical (glycinergic) synapses to modulate OFF cone cell bipolar terminals; these ON and OFF cone bipolar terminals then drive the output neurons, retinal ganglion cells (RGCs), following light increments and decrements, respectively. The AII amacrine cell also makes direct glycinergic synapses with certain RGCs, but it is not well established how many types receive this direct AII input. Here, we investigated functional AII amacrine→RGC synaptic connections in the retina of the guinea pig (Cavia porcellus) by recording inhibitory currents from RGCs in the presence of ionotropic glutamate receptor (iGluR) antagonists. This condition isolates a specific pathway through the AII amacrine cell that does not require iGluRs: cone→ON cone bipolar cell→AII amacrine cell→RGC. These recordings show that AII amacrine cells make direct synapses with OFF Alpha, OFF Delta and a smaller OFF transient RGC type that co-stratifies with OFF Alpha cells. However, AII amacrine cells avoid making synapses with numerous RGC types that co-stratify with the connected RGCs. Selective AII connections ensure that a privileged minority of RGC types receives direct input from the night-vision pathway, independent from OFF bipolar cell activity. Furthermore, these results illustrate the specificity of retinal connections, which cannot be predicted solely by co-stratification of dendrites and axons within the inner plexiform layer.
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Affiliation(s)
- Deborah L Beaudoin
- Department of Ophthalmology & Visual Sciences, University of Michigan, Ann Arbor, Michigan
| | - Mania Kupershtok
- Department of Ophthalmology & Visual Sciences, University of Michigan, Ann Arbor, Michigan
| | - Jonathan B Demb
- Department of Ophthalmology & Visual Sciences, University of Michigan, Ann Arbor, Michigan
- Department of Molecular, Cellular & Developmental Biology, University of Michigan, Ann Arbor, Michigan
- Department of Ophthalmology & Visual Science, Yale University, New Haven, Connecticut
- Department of Cellular & Molecular Physiology, Yale University, New Haven, Connecticut
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12
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Li H, Liu X, Andolina IM, Li X, Lu Y, Spillmann L, Wang W. Asymmetries of Dark and Bright Negative Afterimages Are Paralleled by Subcortical ON and OFF Poststimulus Responses. J Neurosci 2017; 37:1984-1996. [PMID: 28077727 PMCID: PMC6705684 DOI: 10.1523/jneurosci.2021-16.2017] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2016] [Revised: 12/21/2016] [Accepted: 01/02/2017] [Indexed: 01/01/2023] Open
Abstract
Humans are more sensitive to luminance decrements than increments, as evidenced by lower thresholds and shorter latencies for dark stimuli. This asymmetry is consistent with results of neurophysiological recordings in dorsal lateral geniculate nucleus (dLGN) and primary visual cortex (V1) of cat and monkey. Specifically, V1 population responses demonstrate that darks elicit higher levels of activation than brights, and the latency of OFF responses in dLGN and V1 is shorter than that of ON responses. The removal of a dark or bright disc often generates the perception of a negative afterimage, and here we ask whether there also exist asymmetries for negative afterimages elicited by dark and bright discs. If so, do the poststimulus responses of subcortical ON and OFF cells parallel such afterimage asymmetries? To test these hypotheses, we performed psychophysical experiments in humans and single-cell/S-potential recordings in cat dLGN. Psychophysically, we found that bright afterimages elicited by luminance decrements are stronger and last longer than dark afterimages elicited by luminance increments of equal sizes. Neurophysiologically, we found that ON cells responded to the removal of a dark disc with higher firing rates that were maintained for longer than OFF cells to the removal of a bright disc. The ON and OFF cell asymmetry was most pronounced at long stimulus durations in the dLGN. We conclude that subcortical response strength differences between ON and OFF channels parallel the asymmetries between bright and dark negative afterimages, further supporting a subcortical origin of bright and dark afterimage perception.SIGNIFICANCE STATEMENT Afterimages are physiological aftereffects following stimulation of the eye, the study of which helps us to understand how our visual brain generates visual perception in the absence of physical stimuli. We report, for the first time to our knowledge, asymmetries between bright and dark negative afterimages elicited by luminance decrements and increments, respectively. Bright afterimages are stronger and last longer than dark afterimages. Subcortical neuronal recordings of poststimulus responses of ON and OFF cells reveal similar asymmetries with respect to response strength and duration. Our results suggest that subcortical differences between ON and OFF channels help explain intensity and duration asymmetries between bright and dark afterimages, supporting the notion of a subcortical origin of bright and dark afterimages.
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Affiliation(s)
- Hui Li
- Institute of Neuroscience, State Key Laboratory of Neuroscience, Key Laboratory of Primate Neurobiology, Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai 200031, China
- University of Chinese Academy of Sciences, Shanghai 200031, China, and
| | - Xu Liu
- Institute of Neuroscience, State Key Laboratory of Neuroscience, Key Laboratory of Primate Neurobiology, Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai 200031, China
- University of Chinese Academy of Sciences, Shanghai 200031, China, and
| | - Ian M Andolina
- Institute of Neuroscience, State Key Laboratory of Neuroscience, Key Laboratory of Primate Neurobiology, Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai 200031, China,
| | - Xiaohong Li
- Institute of Neuroscience, State Key Laboratory of Neuroscience, Key Laboratory of Primate Neurobiology, Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai 200031, China
| | - Yiliang Lu
- Institute of Neuroscience, State Key Laboratory of Neuroscience, Key Laboratory of Primate Neurobiology, Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai 200031, China
| | - Lothar Spillmann
- Department of Neurology, University of Freiburg, 79085 Freiburg, Germany
| | - Wei Wang
- Institute of Neuroscience, State Key Laboratory of Neuroscience, Key Laboratory of Primate Neurobiology, Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai 200031, China,
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13
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A Mammalian Retinal Ganglion Cell Implements a Neuronal Computation That Maximizes the SNR of Its Postsynaptic Currents. J Neurosci 2016; 37:1468-1478. [PMID: 28039376 DOI: 10.1523/jneurosci.2814-16.2016] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2016] [Revised: 11/30/2016] [Accepted: 12/06/2016] [Indexed: 01/01/2023] Open
Abstract
Neurons perform computations by integrating excitatory and inhibitory synaptic inputs. Yet, it is rarely understood what computation is being performed, or how much excitation or inhibition this computation requires. Here we present evidence for a neuronal computation that maximizes the signal-to-noise power ratio (SNR). We recorded from OFF delta retinal ganglion cells in the guinea pig retina and monitored synaptic currents that were evoked by visual stimulation (flashing dark spots). These synaptic currents were mediated by a decrease in an outward current from inhibitory synapses (disinhibition) combined with an increase in an inward current from excitatory synapses. We found that the SNR of combined excitatory and disinhibitory currents was voltage sensitive, peaking at membrane potentials near resting potential. At the membrane potential for maximal SNR, the amplitude of each current, either excitatory or disinhibitory, was proportional to its SNR. Such proportionate scaling is the theoretically best strategy for combining excitatory and disinhibitory currents to maximize the SNR of their combined current. Moreover, as spot size or contrast changed, the amplitudes of excitatory and disinhibitory currents also changed but remained in proportion to their SNRs, indicating a dynamic rebalancing of excitatory and inhibitory currents to maximize SNR.SIGNIFICANCE STATEMENT We present evidence that the balance of excitatory and disinhibitory inputs to a type of retinal ganglion cell maximizes the signal-to-noise ratio power ratio (SNR) of its postsynaptic currents. This is significant because chemical synapses on a retinal ganglion cell require the probabilistic release of transmitter. Consequently, when the same visual stimulus is presented repeatedly, postsynaptic currents vary in amplitude. Thus, maximizing SNR may be a strategy for producing the most reliable signal possible given the inherent unreliability of synaptic transmission.
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14
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Balakrishnan V, Puthussery T, Kim MH, Taylor WR, von Gersdorff H. Synaptic Vesicle Exocytosis at the Dendritic Lobules of an Inhibitory Interneuron in the Mammalian Retina. Neuron 2015; 87:563-75. [PMID: 26247863 DOI: 10.1016/j.neuron.2015.07.016] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2015] [Revised: 05/07/2015] [Accepted: 07/20/2015] [Indexed: 11/16/2022]
Abstract
Ribbon synapses convey sustained and phasic excitatory drive within retinal microcircuits. However, the properties of retinal inhibitory synapses are less well known. AII-amacrine cells are interneurons in the retina that exhibit large glycinergic synapses at their dendritic lobular appendages. Using membrane capacitance measurements, we observe robust exocytosis elicited by the opening of L-type Ca(2+) channels located on the lobular appendages. Two pools of synaptic vesicles were detected: a small, rapidly releasable pool and a larger and more slowly releasable pool. Depending on the stimulus, either paired-pulse depression or facilitation could be elicited. During early postnatal maturation, the coupling of the exocytosis Ca(2+)-sensor to Ca(2+) channel becomes tighter. Light-evoked depolarizations of the AII-amacrine cell elicited exocytosis that was graded to light intensity. Our results suggest that AII-amacrine cell synapses are capable of providing both phasic and sustained inhibitory input to their postsynaptic partners without the benefit of synaptic ribbons.
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Affiliation(s)
| | - Theresa Puthussery
- Department of Ophthalmology, Casey Eye Institute, Oregon Health & Science University, Portland, OR 97239, USA
| | - Mean-Hwan Kim
- The Vollum Institute, Oregon Health & Science University, Portland, OR 97239, USA
| | - W Rowland Taylor
- Department of Ophthalmology, Casey Eye Institute, Oregon Health & Science University, Portland, OR 97239, USA
| | - Henrique von Gersdorff
- The Vollum Institute, Oregon Health & Science University, Portland, OR 97239, USA; Department of Ophthalmology, Casey Eye Institute, Oregon Health & Science University, Portland, OR 97239, USA.
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15
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Sarnaik R, Chen H, Liu X, Cang J. Genetic disruption of the On visual pathway affects cortical orientation selectivity and contrast sensitivity in mice. J Neurophysiol 2014; 111:2276-86. [PMID: 24598523 DOI: 10.1152/jn.00558.2013] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
The retina signals stimulus contrast via parallel On and Off pathways and sends the information to higher visual centers. Here we study the role of the On pathway using mice that have null mutations in the On-specific GRM6 receptor in the retina (Pinto LH, Vitaterna MH, Shimomura K, Siepka SM, Balannik V, McDearmon EL, Omura C, Lumayag S, Invergo BM, Brandon M, Glawe B, Cantrell DR, Donald R, Inayat S, Olvera MA, Vessey KA, Kirstan A, McCall MA, Maddox D, Morgans CW, Young B, Pletcher MT, Mullins RF, Troy JB, Takahashi JS. Vis Neurosci 24: 111-123, 2007; Maddox DM, Vessey KA, Yarbrough GL, Invergo BM, Cantrell DR, Inayat S, Balannik V, Hicks WL, Hawes NL, Byers S, Smith RS, Hurd R, Howell D, Gregg RG, Chang B, Naggert JK, Troy JB, Pinto LH, Nishina PM, McCall MA. J Physiol 586: 4409-4424, 2008). In these "nob" mice, single unit recordings in the primary visual cortex (V1) reveal degraded selectivity for orientations due to an increased response at nonpreferred orientations. Contrast sensitivity in the nob mice is reduced with severe deficits at low contrast, consistent with the phenotype of night blindness in human patients with mutations in Grm6. These cortical deficits can be largely explained by reduced input drive and increased response variability seen in nob V1. Interestingly, increased variability is also observed in the superior colliculus of these mice but does not affect its tuning properties. Further, the increased response variability in the nob mice is traced to the retina, a result phenocopied by acute pharmacological blockade of the On pathway in wild-type retina. Together, our results suggest that the On and Off pathways normally interact to increase response reliability in the retina, which in turn propagates to various central visual targets and affects their functional properties.
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Affiliation(s)
- Rashmi Sarnaik
- Department of Neurobiology, Northwestern University, Evanston, Illinois; Interdepartmental Neuroscience Program, Northwestern University, Evanston, Illinois; and
| | - Hui Chen
- Department of Ophthalmology, Northwestern University, Evanston, Illinois
| | - Xiaorong Liu
- Department of Neurobiology, Northwestern University, Evanston, Illinois; Department of Ophthalmology, Northwestern University, Evanston, Illinois
| | - Jianhua Cang
- Department of Neurobiology, Northwestern University, Evanston, Illinois;
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16
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Marc RE, Jones BW, Watt CB, Anderson JR, Sigulinsky C, Lauritzen S. Retinal connectomics: towards complete, accurate networks. Prog Retin Eye Res 2013; 37:141-62. [PMID: 24016532 PMCID: PMC4045117 DOI: 10.1016/j.preteyeres.2013.08.002] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2012] [Revised: 08/22/2013] [Accepted: 08/28/2013] [Indexed: 11/17/2022]
Abstract
Connectomics is a strategy for mapping complex neural networks based on high-speed automated electron optical imaging, computational assembly of neural data volumes, web-based navigational tools to explore 10(12)-10(15) byte (terabyte to petabyte) image volumes, and annotation and markup tools to convert images into rich networks with cellular metadata. These collections of network data and associated metadata, analyzed using tools from graph theory and classification theory, can be merged with classical systems theory, giving a more completely parameterized view of how biologic information processing systems are implemented in retina and brain. Networks have two separable features: topology and connection attributes. The first findings from connectomics strongly validate the idea that the topologies of complete retinal networks are far more complex than the simple schematics that emerged from classical anatomy. In particular, connectomics has permitted an aggressive refactoring of the retinal inner plexiform layer, demonstrating that network function cannot be simply inferred from stratification; exposing the complex geometric rules for inserting different cells into a shared network; revealing unexpected bidirectional signaling pathways between mammalian rod and cone systems; documenting selective feedforward systems, novel candidate signaling architectures, new coupling motifs, and the highly complex architecture of the mammalian AII amacrine cell. This is but the beginning, as the underlying principles of connectomics are readily transferrable to non-neural cell complexes and provide new contexts for assessing intercellular communication.
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Affiliation(s)
- Robert E. Marc
- University of Utah School of Medicine, Department of Ophthalmology / John A. Moran Eye Center, 65 Mario Capecchi Dr, Salt Lake City UT 84132
| | - Bryan W. Jones
- University of Utah School of Medicine, Department of Ophthalmology / John A. Moran Eye Center, 65 Mario Capecchi Dr, Salt Lake City UT 84132
| | - Carl B. Watt
- University of Utah School of Medicine, Department of Ophthalmology / John A. Moran Eye Center, 65 Mario Capecchi Dr, Salt Lake City UT 84132
| | - James R. Anderson
- University of Utah School of Medicine, Department of Ophthalmology / John A. Moran Eye Center, 65 Mario Capecchi Dr, Salt Lake City UT 84132
| | - Crystal Sigulinsky
- University of Utah School of Medicine, Department of Ophthalmology / John A. Moran Eye Center, 65 Mario Capecchi Dr, Salt Lake City UT 84132
| | - Scott Lauritzen
- University of Utah School of Medicine, Department of Ophthalmology / John A. Moran Eye Center, 65 Mario Capecchi Dr, Salt Lake City UT 84132
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