1
|
Avilés EC, Wang SK, Patel S, Shi S, Lin L, Kefalov VJ, Goodrich LV, Cepko CL, Xue Y. High temporal frequency light response in mouse retina requires FAT3 signaling in bipolar cells. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.11.02.565326. [PMID: 37961274 PMCID: PMC10635074 DOI: 10.1101/2023.11.02.565326] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2023]
Abstract
Vision is initiated by the reception of light by photoreceptors and subsequent processing via downstream retinal neurons. Proper cellular organization depends on the multi-functional tissue polarity protein FAT3, which is required for amacrine cell connectivity and retinal lamination. Here we investigated the retinal function of Fat3 mutant mice and found decreases in physiological and perceptual responses to high frequency flashes. These defects did not correlate with abnormal amacrine cell wiring, pointing instead to a role in bipolar cell subtypes that also express FAT3. The role of FAT3 in the response to high temporal frequency flashes depends upon its ability to transduce an intracellular signal. Mechanistically, FAT3 binds to the synaptic protein PTPσ, intracellularly, and is required to localize GRIK1 to OFF-cone bipolar cell synapses with cone photoreceptors. These findings expand the repertoire of FAT3's functions and reveal its importance in bipolar cells for high frequency light response.
Collapse
Affiliation(s)
- Evelyn C Avilés
- Department of Neurobiology, Blavatnik Institute, Harvard Medical School, Boston, MA 02115
- Facultad de Ciencias Biologicas, Pontificia Universidad Catolica de Chile, Santiago, Chile
| | - Sean K Wang
- Departments of Genetics and Ophthalmology, Harvard Medical School, Boston, MA 02115
- Howard Hughes Medical Institute, Boston, MA 02115
| | - Sarina Patel
- Department of Neurobiology, Blavatnik Institute, Harvard Medical School, Boston, MA 02115
| | - Shuxiang Shi
- Lingang Laboratory, Shanghai, China, 200031
- School of Life Science and Technology, ShanghaiTech University, Shanghai, China, 201210
| | - Lucas Lin
- Departments of Genetics and Ophthalmology, Harvard Medical School, Boston, MA 02115
| | - Vladimir J Kefalov
- Gavin Herbert Eye Institute & Center for Translational Vision Research, University of California, Irvine, CA 92697
| | - Lisa V Goodrich
- Department of Neurobiology, Blavatnik Institute, Harvard Medical School, Boston, MA 02115
| | - Constance L Cepko
- Departments of Genetics and Ophthalmology, Harvard Medical School, Boston, MA 02115
- Howard Hughes Medical Institute, Boston, MA 02115
| | - Yunlu Xue
- Departments of Genetics and Ophthalmology, Harvard Medical School, Boston, MA 02115
- Lingang Laboratory, Shanghai, China, 200031
- Lead contact
| |
Collapse
|
2
|
Hasan N, Gregg RG. Cone Synaptic function is modulated by the leucine rich repeat (LRR) adhesion molecule LRFN2. eNeuro 2024; 11:ENEURO.0120-23.2024. [PMID: 38408870 PMCID: PMC10957230 DOI: 10.1523/eneuro.0120-23.2024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2023] [Revised: 02/11/2024] [Accepted: 02/18/2024] [Indexed: 02/28/2024] Open
Abstract
Daylight vision is mediated by cone photoreceptors in vertebrates, which synapse with bipolar cells (BCs) and horizontal (HCs) cells. This cone synapse is functionally and anatomically complex, connecting to 8 types of depolarizing BCs (DBCs) and 5 types of hyperpolarizing BCs (HBCs) in mice. The dendrites of DBCs and HCs cells make invaginating ribbon synapses with the cone axon terminal, while HBCs form flat synapses with the cone pedicles. The molecular architecture that underpins this organization is relatively poorly understood. To identify new proteins involved in synapse formation and function we used an unbiased proteomic approach and identified LRFN2 (leucine-rich repeat and fibronectin III domain-containing 2) as a component of the DBC signaling complex. LRFN2 is selectively expressed at cone terminals and co-localizes with PNA, and other DBC signalplex members. In LRFN2 deficient mice, the synaptic markers: LRIT3, ELFN2, mGluR6, TRPM1 and GPR179 are properly localized. Similarly, LRFN2 expression and localization is not dependent on these synaptic proteins. In the absence of LRFN2 the cone-mediated photopic electroretinogram b-wave amplitude is reduced at the brightest flash intensities. These data demonstrate that LRFN2 absence compromises normal synaptic transmission between cones and cone DBCs.Significance Statement Signaling between cone photoreceptors and the downstream bipolar cells is critical to normal vision. Cones synapse with 13 different types of bipolar cells forming an invaginating ribbon synapses with 8 types, and flat synapses with 5 types, to form one of the most complex synapses in the brain. In this report a new protein, LRFN2 (leucine-rich repeat and fibronectin III domain-containing 2), was identified that is expressed at the cone synapse. Using Lrfn2 knockout mice we show LRFN2 is required for the normal cone signaling.
Collapse
Affiliation(s)
- Nazarul Hasan
- Departments of Biochemistry & Molecular Genetics, University of Louisville, Louisville, Kentucky 40202
- Ophthalmology & Visual Sciences, University of Louisville, Louisville, Kentucky 40202
| | - Ronald G. Gregg
- Departments of Biochemistry & Molecular Genetics, University of Louisville, Louisville, Kentucky 40202
- Ophthalmology & Visual Sciences, University of Louisville, Louisville, Kentucky 40202
| |
Collapse
|
3
|
Park SJ, Lei W, Pisano J, Orpia A, Minehart J, Pottackal J, Hanke-Gogokhia C, Zapadka TE, Clarkson-Paredes C, Popratiloff A, Ross SE, Singer JH, Demb JB. Molecular identification of wide-field amacrine cells in mouse retina that encode stimulus orientation. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.12.28.573580. [PMID: 38234775 PMCID: PMC10793454 DOI: 10.1101/2023.12.28.573580] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2024]
Abstract
Visual information processing is sculpted by a diverse group of inhibitory interneurons in the retina called amacrine cells. Yet, for most of the >60 amacrine cell types, molecular identities and specialized functional attributes remain elusive. Here, we developed an intersectional genetic strategy to target a group of wide-field amacrine cells (WACs) in mouse retina that co-express the transcription factor Bhlhe22 and the Kappa Opioid Receptor (KOR; B/K WACs). B/K WACs feature straight, unbranched dendrites spanning over 0.5 mm (∼15° visual angle) and produce non-spiking responses to either light increments or decrements. Two-photon dendritic population imaging reveals Ca 2+ signals tuned to the physical orientations of B/K WAC dendrites, signifying a robust structure-function alignment. B/K WACs establish divergent connections with multiple retinal neurons, including unexpected connections with non-orientation-tuned ganglion cells and bipolar cells. Our work sets the stage for future comprehensive investigations of the most enigmatic group of retinal neurons: WACs.
Collapse
|
4
|
Kerschensteiner D. Losing, preserving, and restoring vision from neurodegeneration in the eye. Curr Biol 2023; 33:R1019-R1036. [PMID: 37816323 PMCID: PMC10575673 DOI: 10.1016/j.cub.2023.08.044] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/12/2023]
Abstract
The retina is a part of the brain that sits at the back of the eye, looking out onto the world. The first neurons of the retina are the rod and cone photoreceptors, which convert changes in photon flux into electrical signals that are the basis of vision. Rods and cones are frequent targets of heritable neurodegenerative diseases that cause visual impairment, including blindness, in millions of people worldwide. This review summarizes the diverse genetic causes of inherited retinal degenerations (IRDs) and their convergence onto common pathogenic mechanisms of vision loss. Currently, there are few effective treatments for IRDs, but recent advances in disparate areas of biology and technology (e.g., genome editing, viral engineering, 3D organoids, optogenetics, semiconductor arrays) discussed here enable promising efforts to preserve and restore vision in IRD patients with implications for neurodegeneration in less approachable brain areas.
Collapse
Affiliation(s)
- Daniel Kerschensteiner
- Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, St. Louis, MO 63110, USA; Department of Neuroscience, Washington University School of Medicine, St. Louis, MO 63110, USA; Department of Biomedical Engineering, Washington University School of Medicine, St. Louis, MO 63110, USA.
| |
Collapse
|
5
|
Vöcking O, Famulski JK. A temporal single cell transcriptome atlas of zebrafish anterior segment development. Sci Rep 2023; 13:5656. [PMID: 37024546 PMCID: PMC10079958 DOI: 10.1038/s41598-023-32212-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2022] [Accepted: 03/24/2023] [Indexed: 04/08/2023] Open
Abstract
Anterior segment dysgenesis (ASD), resulting in vision impairment, stems from maldevelopment of anterior segment (AS) tissues. Incidence of ASD has been linked to malfunction of periocular mesenchyme cells (POM). POM cells specify into anterior segment mesenchyme (ASM) cells which colonize and produce AS tissues. In this study we uncover ASM developmental trajectories associated with formation of the AS. Using a transgenic line of zebrafish that fluorescently labels the ASM throughout development, Tg[foxc1b:GFP], we isolated GFP+ ASM cells at several developmental timepoints (48-144 hpf) and performed single cell RNA sequencing. Clustering analysis indicates subdifferentiation of ASM as early as 48 hpf and subsequent diversification into corneal epithelium/endothelium/stroma, or annular ligament (AL) lineages. Tracking individual clusters reveals common developmental pathways, up to 72 hpf, for the AL and corneal endothelium/stroma and distinct pathways for corneal epithelium starting at 48 hpf. Spatiotemporal validation of over 80 genes found associated with AS development demonstrates a high degree of conservation with mammalian trabecular meshwork and corneal tissues. In addition, we characterize thirteen novel genes associated with annular ligament and seven with corneal development. Overall, the data provide a molecular verification of the long-standing hypothesis that POM derived ASM give rise to AS tissues and highlight the high degree of conservation between zebrafish and mammals.
Collapse
Affiliation(s)
- Oliver Vöcking
- Department of Biology, University of Kentucky, Lexington, USA
| | - J K Famulski
- Department of Biology, University of Kentucky, Lexington, USA.
| |
Collapse
|
6
|
Sladek AL, Thoreson WB. Using optogenetics to dissect rod inputs to OFF ganglion cells in the mouse retina. FRONTIERS IN OPHTHALMOLOGY 2023; 3:1146785. [PMID: 37426783 PMCID: PMC10327572 DOI: 10.3389/fopht.2023.1146785] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 07/11/2023]
Abstract
Introduction Light responses of rod photoreceptor cells traverse the retina through three pathways. The primary pathway involves synapses from rods to ON-type rod bipolar cells with OFF signals reaching retinal ganglion cells (RGCs) via sign-inverting glycinergic synapses. Secondly, rod signals can enter cones through gap junctions. Finally, rods can synapse directly onto cone OFF bipolar cells. Methods To analyze these pathways, we obtained whole cell recordings from OFF-type α RGCs in mouse retinas while expressing channelrhodopsin-2 in rods and/or cones. Results Optogenetic stimulation of rods or cones evoked large fast currents in OFF RGCs. Blocking the primary rod pathway with L-AP4 and/or strychnine reduced rod-driven optogenetic currents in OFF RGCs by ~1/3. Blocking kainate receptors of OFF cone bipolar cells suppressed both rod- and cone-driven optogenetic currents in OFF RGCs. Inhibiting gap junctions between rods and cones with mecloflenamic acid or quinpirole reduced rod-driven responses in OFF RGCs. Eliminating the exocytotic Ca2+ sensor, synaptotagmin 1 (Syt1), from cones abolished cone-driven optogenetic responses in RGCs. Rod-driven currents were not significantly reduced after isolating the secondary pathway by eliminating Syt1 and synaptotagmin 7 (Syt7) to block synaptic release from rods. Eliminating Syt1 from both rods and cones abolished responses to optogenetic stimulation. In Cx36 KO retinas lacking rod-cone gap junctions, optogenetic activation of rods evoked small and slow responses in most OFF RGCs suggesting rod signals reached them through an indirect pathway. Two OFF cells showed faster responses consistent with more direct input from cone OFF bipolar cells. Discussion These data show that the secondary rod pathway supports robust inputs into OFF α RGCs and suggests the tertiary pathway recruits both direct and indirect inputs.
Collapse
Affiliation(s)
- Asia L. Sladek
- Truhlsen Eye Institute and Department of Ophthalmology and Visual Sciences, University of Nebraska Medical Center, Omaha, NE, United States
| | - Wallace B. Thoreson
- Truhlsen Eye Institute and Department of Ophthalmology and Visual Sciences, University of Nebraska Medical Center, Omaha, NE, United States
- Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, NE, United States
| |
Collapse
|
7
|
He L, He Y, Ma L, Huang T. A theoretical model reveals specialized synaptic depressions and temporal frequency tuning in retinal parallel channels. Front Comput Neurosci 2022; 16:1034446. [DOI: 10.3389/fncom.2022.1034446] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2022] [Accepted: 10/27/2022] [Indexed: 11/18/2022] Open
Abstract
In the Outer Plexiform Layer of a retina, a cone pedicle provides synaptic inputs for multiple cone bipolar cell (CBC) subtypes so that each subtype formats a parallelized processing channel to filter visual features from the environment. Due to the diversity of short-term depressions among cone-CBC contacts, these channels have different temporal frequency tunings. Here, we propose a theoretical model based on the hierarchy Linear-Nonlinear-Synapse framework to link the synaptic depression and the neural activities of the cone-CBC circuit. The model successfully captures various frequency tunings of subtype-specialized channels and infers synaptic depression recovery time constants inside circuits. Furthermore, the model can predict frequency-tuning behaviors based on synaptic activities. With the prediction of region-specialized UV cone parallel channels, we suggest the acute zone in the zebrafish retina supports detecting light-off events at high temporal frequencies.
Collapse
|
8
|
Fitzpatrick MJ, Kerschensteiner D. Homeostatic plasticity in the retina. Prog Retin Eye Res 2022; 94:101131. [PMID: 36244950 DOI: 10.1016/j.preteyeres.2022.101131] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Revised: 09/25/2022] [Accepted: 09/28/2022] [Indexed: 02/07/2023]
Abstract
Vision begins in the retina, whose intricate neural circuits extract salient features of the environment from the light entering our eyes. Neurodegenerative diseases of the retina (e.g., inherited retinal degenerations, age-related macular degeneration, and glaucoma) impair vision and cause blindness in a growing number of people worldwide. Increasing evidence indicates that homeostatic plasticity (i.e., the drive of a neural system to stabilize its function) can, in principle, preserve retinal function in the face of major perturbations, including neurodegeneration. Here, we review the circumstances and events that trigger homeostatic plasticity in the retina during development, sensory experience, and disease. We discuss the diverse mechanisms that cooperate to compensate and the set points and outcomes that homeostatic retinal plasticity stabilizes. Finally, we summarize the opportunities and challenges for unlocking the therapeutic potential of homeostatic plasticity. Homeostatic plasticity is fundamental to understanding retinal development and function and could be an important tool in the fight to preserve and restore vision.
Collapse
|
9
|
Spampinato GLB, Ronzitti E, Zampini V, Ferrari U, Trapani F, Khabou H, Agraval A, Dalkara D, Picaud S, Papagiakoumou E, Marre O, Emiliani V. All-optical inter-layers functional connectivity investigation in the mouse retina. CELL REPORTS METHODS 2022; 2:100268. [PMID: 36046629 PMCID: PMC9421538 DOI: 10.1016/j.crmeth.2022.100268] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/25/2022] [Revised: 06/03/2022] [Accepted: 07/19/2022] [Indexed: 06/01/2023]
Abstract
We developed a multi-unit microscope for all-optical inter-layers circuits interrogation. The system performs two-photon (2P) functional imaging and 2P multiplexed holographic optogenetics at axially distinct planes. We demonstrated the capability of the system to map, in the mouse retina, the functional connectivity between rod bipolar cells (RBCs) and ganglion cells (GCs) by activating single or defined groups of RBCs while recording the evoked response in the GC layer with cell-type specificity and single-cell resolution. We then used a logistic model to probe the functional connectivity between cell types by deriving the "cellular receptive field" describing how RBCs impact each GC type. With the capability to simultaneously image and control neuronal activity at axially distinct planes, the system enables a precise interrogation of multi-layered circuits. Understanding this information transfer is a promising avenue to dissect complex neural circuits and understand the neural basis of computations.
Collapse
Affiliation(s)
| | - Emiliano Ronzitti
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, 75012 Paris, France
| | - Valeria Zampini
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, 75012 Paris, France
| | - Ulisse Ferrari
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, 75012 Paris, France
| | - Francesco Trapani
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, 75012 Paris, France
| | - Hanen Khabou
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, 75012 Paris, France
| | | | - Deniz Dalkara
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, 75012 Paris, France
| | - Serge Picaud
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, 75012 Paris, France
| | | | - Olivier Marre
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, 75012 Paris, France
| | - Valentina Emiliani
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, 75012 Paris, France
| |
Collapse
|
10
|
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] [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.
Collapse
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:
| |
Collapse
|
11
|
Ichinose T, Habib S. ON and OFF Signaling Pathways in the Retina and the Visual System. FRONTIERS IN OPHTHALMOLOGY 2022; 2:989002. [PMID: 36926308 PMCID: PMC10016624 DOI: 10.3389/fopht.2022.989002] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Visual processing starts at the retina of the eye, and signals are then transferred primarily to the visual cortex and the tectum. In the retina, multiple neural networks encode different aspects of visual input, such as color and motion. Subsequently, multiple neural streams in parallel convey unique aspects of visual information to cortical and subcortical regions. Bipolar cells, which are the second order neurons of the retina, separate visual signals evoked by light and dark contrasts and encode them to ON and OFF pathways, respectively. The interplay between ON and OFF neural signals is the foundation for visual processing for object contrast which underlies higher order stimulus processing. ON and OFF pathways have been classically thought to signal in a mirror-symmetric manner. However, while these two pathways contribute synergistically to visual perception in some instances, they have pronounced asymmetries suggesting independent operation in other cases. In this review, we summarize the role of the ON-OFF dichotomy in visual signaling, aiming to contribute to the understanding of visual recognition.
Collapse
Affiliation(s)
- Tomomi Ichinose
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, Detroit, Michigan, USA
- Correspondence: Tomomi Ichinose, MD, PhD,
| | - Samar Habib
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, Detroit, Michigan, USA
- Department of Medical Parasitology, Mansoura Faculty of Medicine, Mansoura University, Mansoura, Egypt
| |
Collapse
|
12
|
Abstract
Our sense of sight relies on photoreceptors, which transduce photons into the nervous system's electrochemical interpretation of the visual world. These precious photoreceptors can be disrupted by disease, injury, and aging. Once photoreceptors start to die, but before blindness occurs, the remaining retinal circuitry can withstand, mask, or exacerbate the photoreceptor deficit and potentially be receptive to newfound therapies for vision restoration. To maximize the retina's receptivity to therapy, one must understand the conditions that influence the state of the remaining retina. In this review, we provide an overview of the retina's structure and function in health and disease. We analyze a collection of observations on photoreceptor disruption and generate a predictive model to identify parameters that influence the retina's response. Finally, we speculate on whether the retina, with its remarkable capacity to function over light levels spanning nine orders of magnitude, uses these same adaptational mechanisms to withstand and perhaps mask photoreceptor loss.
Collapse
Affiliation(s)
- Joo Yeun Lee
- Department of Ophthalmology, University of California, San Francisco, California 94143, USA; , , ,
| | - Rachel A Care
- Department of Ophthalmology, University of California, San Francisco, California 94143, USA; , , ,
| | - Luca Della Santina
- Department of Ophthalmology, University of California, San Francisco, California 94143, USA; , , ,
- Bakar Computational Health Sciences Institute, University of California, San Francisco, California 94143, USA
| | - Felice A Dunn
- Department of Ophthalmology, University of California, San Francisco, California 94143, USA; , , ,
| |
Collapse
|
13
|
Pottackal J, Singer JH, Demb JB. Computational and Molecular Properties of Starburst Amacrine Cell Synapses Differ With Postsynaptic Cell Type. Front Cell Neurosci 2021; 15:660773. [PMID: 34381333 PMCID: PMC8351878 DOI: 10.3389/fncel.2021.660773] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Accepted: 06/08/2021] [Indexed: 11/22/2022] Open
Abstract
A presynaptic neuron can increase its computational capacity by transmitting functionally distinct signals to each of its postsynaptic cell types. To determine whether such computational specialization occurs over fine spatial scales within a neurite arbor, we investigated computation at output synapses of the starburst amacrine cell (SAC), a critical component of the classical direction-selective (DS) circuit in the retina. The SAC is a non-spiking interneuron that co-releases GABA and acetylcholine and forms closely spaced (<5 μm) inhibitory synapses onto two postsynaptic cell types: DS ganglion cells (DSGCs) and neighboring SACs. During dynamic optogenetic stimulation of SACs in mouse retina, whole-cell recordings of inhibitory postsynaptic currents revealed that GABAergic synapses onto DSGCs exhibit stronger low-pass filtering than those onto neighboring SACs. Computational analyses suggest that this filtering difference can be explained primarily by presynaptic properties, rather than those of the postsynaptic cells per se. Consistent with functionally diverse SAC presynapses, blockade of N-type voltage-gated calcium channels abolished GABAergic currents in SACs but only moderately reduced GABAergic and cholinergic currents in DSGCs. These results jointly demonstrate how specialization of synaptic outputs could enhance parallel processing in a compact interneuron over fine spatial scales. Moreover, the distinct transmission kinetics of GABAergic SAC synapses are poised to support the functional diversity of inhibition within DS circuitry.
Collapse
Affiliation(s)
- Joseph Pottackal
- Interdepartmental Neuroscience Program, Yale University, New Haven, CT, United States.,Department of Biology, University of Maryland, College Park, College Park, MD, United States
| | - Joshua H Singer
- Department of Biology, University of Maryland, College Park, College Park, MD, United States
| | - Jonathan B Demb
- Interdepartmental Neuroscience Program, Yale University, New Haven, CT, United States.,Department of Ophthalmology and Visual Science, Yale University, New Haven, CT, United States.,Department of Cellular and Molecular Physiology, Yale University, New Haven, CT, United States.,Department of Neuroscience, Yale University, New Haven, CT, United States
| |
Collapse
|
14
|
Ding RF, Yu Q, Liu K, Du J, Yin HJ, Ji ZL. Gene network analyses unveil possible molecular basis underlying drug-induced glaucoma. BMC Med Genomics 2021; 14:109. [PMID: 33874942 PMCID: PMC8056654 DOI: 10.1186/s12920-021-00960-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2021] [Accepted: 04/07/2021] [Indexed: 11/25/2022] Open
Abstract
BACKGROUND Drug-induced glaucoma (DIG) is a kind of serious adverse drug reaction that can cause irreversible blindness. Up-to-date, the molecular mechanism of DIG largely remains unclear yet due to the medical complexity of glaucoma onset. METHODS In this study, we conducted data mining of tremendous historical adverse drug events and genome-wide drug-regulated gene signatures to identify glaucoma-associated drugs. Upon these drugs, we carried out serial network analyses, including the weighted gene co-expression network analysis (WGCNA), to illustrate the gene interaction network underlying DIG. Furthermore, we applied pathogenic risk assessment to discover potential biomarker genes for DIG. RESULTS As the results, we discovered 13 highly glaucoma-associated drugs, a glaucoma-related gene network, and 55 glaucoma-susceptible genes. These genes likely played central roles in triggering DIGs via an integrative mechanism of phototransduction dysfunction, intracellular calcium homeostasis disruption, and retinal ganglion cell death. Further pathogenic risk analysis manifested that a panel of nine genes, particularly OTOF gene, could serve as potential biomarkers for early-onset DIG prognosis. CONCLUSIONS This study elucidates the possible molecular basis underlying DIGs systematically for the first time. It also provides prognosis clues for early-onset glaucoma and thus assists in designing better therapeutic regimens.
Collapse
Affiliation(s)
- Ruo-Fan Ding
- State Key Laboratory of Stress Cell Biology, School of Life Sciences, Xiamen University, Xiamen, 361102, Fujian, People's Republic of China
| | - Qian Yu
- State Key Laboratory of Stress Cell Biology, School of Life Sciences, Xiamen University, Xiamen, 361102, Fujian, People's Republic of China
| | - Ke Liu
- State Key Laboratory of Stress Cell Biology, School of Life Sciences, Xiamen University, Xiamen, 361102, Fujian, People's Republic of China
| | - Juan Du
- State Key Laboratory of Stress Cell Biology, School of Life Sciences, Xiamen University, Xiamen, 361102, Fujian, People's Republic of China
| | - Hua-Jun Yin
- State Key Laboratory of Stress Cell Biology, School of Life Sciences, Xiamen University, Xiamen, 361102, Fujian, People's Republic of China
| | - Zhi-Liang Ji
- State Key Laboratory of Stress Cell Biology, School of Life Sciences, Xiamen University, Xiamen, 361102, Fujian, People's Republic of China.
| |
Collapse
|
15
|
Nonlinear spatial integration in retinal bipolar cells shapes the encoding of artificial and natural stimuli. Neuron 2021; 109:1692-1706.e8. [PMID: 33798407 PMCID: PMC8153253 DOI: 10.1016/j.neuron.2021.03.015] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Revised: 01/22/2021] [Accepted: 03/10/2021] [Indexed: 11/21/2022]
Abstract
The retina dissects the visual scene into parallel information channels, which extract specific visual features through nonlinear processing. The first nonlinear stage is typically considered to occur at the output of bipolar cells, resulting from nonlinear transmitter release from synaptic terminals. In contrast, we show here that bipolar cells themselves can act as nonlinear processing elements at the level of their somatic membrane potential. Intracellular recordings from bipolar cells in the salamander retina revealed frequent nonlinear integration of visual signals within bipolar cell receptive field centers, affecting the encoding of artificial and natural stimuli. These nonlinearities provide sensitivity to spatial structure below the scale of bipolar cell receptive fields in both bipolar and downstream ganglion cells and appear to arise at the excitatory input into bipolar cells. Thus, our data suggest that nonlinear signal pooling starts earlier than previously thought: that is, at the input stage of bipolar cells. Some retinal bipolar cells represent visual contrast in a nonlinear fashion These bipolar cells also nonlinearly integrate visual signals over space The spatial nonlinearity affects the encoding of natural stimuli by bipolar cells The nonlinearity results from feedforward input, not from feedback inhibition
Collapse
|
16
|
Babai N, Wittgenstein J, Gierke K, Brandstätter JH, Feigenspan A. The absence of functional bassoon at cone photoreceptor ribbon synapses affects signal transmission at Off cone bipolar cell contacts in mouse retina. Acta Physiol (Oxf) 2021; 231:e13584. [PMID: 33222426 DOI: 10.1111/apha.13584] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2020] [Revised: 10/21/2020] [Accepted: 11/19/2020] [Indexed: 01/05/2023]
Abstract
AIM Off cone bipolar cells of the mammalian retina connect to cone photoreceptor synaptic terminals via non-invaginating flat contacts at a considerable distance from the only established neurotransmitter release site so far, the synaptic ribbon. Diffusion from the ribbon synaptic active zone is considered the most likely mechanism for the neurotransmitter glutamate to reach postsynaptic receptors on the dendritic tips of Off cone bipolar cells. We used a mutant mouse with functionally impaired photoreceptor ribbon synapses to investigate the importance of intact ribbon synaptic active zones for signal transmission at Off cone bipolar cell contacts. METHODS Whole-cell patch-clamp recordings from Off cone bipolar cells in a horizontal slice preparation of wildtype (Bsnwt ) and mutant (BsnΔEx4/5 ) mouse retina were applied to investigate signal transmission between cone photoreceptors and Off cone bipolar cells. The distribution of postsynaptic glutamate receptors in Off cone bipolar cell dendrites was studied using multiplex immunocytochemistry. RESULTS Tonic synaptic activity and evoked release were significantly reduced in mutant animals. Vesicle replenishment rates and the size of the readily releasable pool were likewise decreased. The precisely timed transient current response to light offset changed to a sustained response in the mutant, exemplified by random release events only loosely time-locked to the stimulus. The kainate receptor distribution in postsynaptic Off cone bipolar cell dendritic contacts in BsnΔEx4/5 mice was largely disturbed. CONCLUSION Our results suggest a major role of functional ribbon synaptic active zones for signal transmission and postsynaptic glutamate receptor organization at flat Off cone bipolar cell contacts.
Collapse
Affiliation(s)
- Norbert Babai
- Department of Biology, Animal Physiology FAU Erlangen‐Nürnberg Erlangen Germany
| | - Julia Wittgenstein
- Department of Biology, Animal Physiology FAU Erlangen‐Nürnberg Erlangen Germany
| | - Kaspar Gierke
- Department of Biology, Animal Physiology FAU Erlangen‐Nürnberg Erlangen Germany
| | | | - Andreas Feigenspan
- Department of Biology, Animal Physiology FAU Erlangen‐Nürnberg Erlangen Germany
| |
Collapse
|
17
|
Brymer KJ, Barnes JR, Parsons MP. Entering a new era of quantifying glutamate clearance in health and disease. J Neurosci Res 2021; 99:1598-1617. [PMID: 33618436 DOI: 10.1002/jnr.24810] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2020] [Revised: 01/22/2021] [Accepted: 02/01/2021] [Indexed: 12/21/2022]
Abstract
Glutamate transporter proteins, expressed on both neurons and glia, serve as the main gatekeepers that dictate the spatial and temporal actions of extracellular glutamate. Glutamate is essential to the function of the healthy brain yet paradoxically contributes to the toxicity associated with many neurodegenerative diseases. Rapid transporter-mediated glutamate uptake, primarily occurring at astrocytic processes, tightens the efficiency of excitatory network activity and prevents toxic glutamate build-up in the extracellular space. Glutamate transporter dysfunction is thought to underlie myriad central nervous system (CNS) diseases including Alzheimer and Huntington disease. Over the past few decades, techniques such as biochemical uptake assays and electrophysiological recordings of transporter currents from individual astrocytes have revealed the remarkable ability of the CNS to efficiently clear extracellular glutamate. In more recent years, the rapidly evolving glutamate-sensing "sniffers" now allow researchers to visualize real-time glutamate transients on a millisecond time scale with single synapse spatial resolution in defined cell populations. As we transition to an increased reliance on optical-based methods of glutamate visualization and quantification, it is of utmost importance to understand not only the advantages that glutamate biosensors bring to the table but also the associated caveats and their implications for data interpretation. In this review, we summarize the strengths and limitations of the commonly used methods to quantify glutamate uptake. We then discuss what these techniques, when viewed as a complementary whole, have told us about the brain's ability to regulate glutamate levels, in both health and in the context of neurodegenerative disease.
Collapse
Affiliation(s)
- Kyle J Brymer
- Faculty of Medicine, Division of Biomedical Sciences, Memorial University of Newfoundland, St. John's, NL, Canada
| | - Jocelyn R Barnes
- Faculty of Medicine, Division of Biomedical Sciences, Memorial University of Newfoundland, St. John's, NL, Canada
| | - Matthew P Parsons
- Faculty of Medicine, Division of Biomedical Sciences, Memorial University of Newfoundland, St. John's, NL, Canada
| |
Collapse
|
18
|
Pottackal J, Singer JH, Demb JB. Receptoral Mechanisms for Fast Cholinergic Transmission in Direction-Selective Retinal Circuitry. Front Cell Neurosci 2020; 14:604163. [PMID: 33324168 PMCID: PMC7726240 DOI: 10.3389/fncel.2020.604163] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2020] [Accepted: 10/22/2020] [Indexed: 01/09/2023] Open
Abstract
Direction selectivity represents an elementary sensory computation that can be related to underlying synaptic mechanisms. In mammalian retina, direction-selective ganglion cells (DSGCs) respond strongly to visual motion in a "preferred" direction and weakly to motion in the opposite, "null" direction. The DS mechanism depends on starburst amacrine cells (SACs), which provide null direction-tuned GABAergic inhibition and untuned cholinergic excitation to DSGCs. GABAergic inhibition depends on conventional synaptic transmission, whereas cholinergic excitation apparently depends on paracrine (i.e., non-synaptic) transmission. Despite its paracrine mode of transmission, cholinergic excitation is more transient than GABAergic inhibition, yielding a temporal difference that contributes essentially to the DS computation. To isolate synaptic mechanisms that generate the distinct temporal properties of cholinergic and GABAergic transmission from SACs to DSGCs, we optogenetically stimulated SACs while recording postsynaptic currents (PSCs) from DSGCs in mouse retina. Direct recordings from channelrhodopsin-2-expressing (ChR2+) SACs during quasi-white noise (WN) (0-30 Hz) photostimulation demonstrated precise, graded optogenetic control of SAC membrane current and potential. Linear systems analysis of ChR2-evoked PSCs recorded in DSGCs revealed cholinergic transmission to be faster than GABAergic transmission. A deconvolution-based analysis showed that distinct postsynaptic receptor kinetics fully account for the temporal difference between cholinergic and GABAergic transmission. Furthermore, GABAA receptor blockade prolonged cholinergic transmission, identifying a new functional role for GABAergic inhibition of SACs. Thus, fast cholinergic transmission from SACs to DSGCs arises from at least two distinct mechanisms, yielding temporal properties consistent with conventional synapses despite its paracrine nature.
Collapse
Affiliation(s)
- Joseph Pottackal
- Interdepartmental Neuroscience Program, Yale University, New Haven, CT, United States
| | - Joshua H. Singer
- Department of Biology, University of Maryland, College Park, MD, United States
| | - Jonathan B. Demb
- Interdepartmental Neuroscience Program, Yale University, New Haven, CT, United States
- Department of Ophthalmology and Visual Science, Yale University, New Haven, CT, United States
- Department of Cellular and Molecular Physiology, Yale University, New Haven, CT, United States
- Department of Neuroscience, Yale University, New Haven, CT, United States
| |
Collapse
|
19
|
Li W. Ground squirrel - A cool model for a bright vision. Semin Cell Dev Biol 2020; 106:127-134. [PMID: 32593518 DOI: 10.1016/j.semcdb.2020.06.005] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2020] [Revised: 06/10/2020] [Accepted: 06/10/2020] [Indexed: 01/04/2023]
Abstract
The great evolutionary biologist, Theodosius Dobzhansky, once said, "Nothing in biology makes sense except in the light of evolution." Vision, no doubt, is a poster child for the work of evolution. If it has not already been said, I would humbly add that "Nothing in biology makes sense except in the context of metabolism." Marrying these two thoughts together, when one chooses an animal model for vision research, the ground squirrel jumps out immediately for its unique cone dominant retina, which has evolved for its diurnal lifestyle, and for hibernation-an adaptation to unique metabolic challenges encountered during its winter sojourn.
Collapse
Affiliation(s)
- Wei Li
- Retinal Neurophysiology Section, National Eye Institute, National Institutes of Health, USA.
| |
Collapse
|
20
|
Park SJH, Lieberman EE, Ke JB, Rho N, Ghorbani P, Rahmani P, Jun NY, Lee HL, Kim IJ, Briggman KL, Demb JB, Singer JH. Connectomic analysis reveals an interneuron with an integral role in the retinal circuit for night vision. eLife 2020; 9:e56077. [PMID: 32412412 PMCID: PMC7228767 DOI: 10.7554/elife.56077] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2020] [Accepted: 04/27/2020] [Indexed: 12/28/2022] Open
Abstract
Night vision in mammals depends fundamentally on rod photoreceptors and the well-studied rod bipolar (RB) cell pathway. The central neuron in this pathway, the AII amacrine cell (AC), exhibits a spatially tuned receptive field, composed of an excitatory center and an inhibitory surround, that propagates to ganglion cells, the retina's projection neurons. The circuitry underlying the surround of the AII, however, remains unresolved. Here, we combined structural, functional and optogenetic analyses of the mouse retina to discover that surround inhibition of the AII depends primarily on a single interneuron type, the NOS-1 AC: a multistratified, axon-bearing GABAergic cell, with dendrites in both ON and OFF synaptic layers, but with a pure ON (depolarizing) response to light. Our study demonstrates generally that novel neural circuits can be identified from targeted connectomic analyses and specifically that the NOS-1 AC mediates long-range inhibition during night vision and is a major element of the RB pathway.
Collapse
Affiliation(s)
- Silvia JH Park
- Department of Ophthalmology & Visual Science, Yale UniversityNew HavenUnited States
| | - Evan E Lieberman
- Department of Biology, University of MarylandCollege ParkUnited States
| | - Jiang-Bin Ke
- Department of Biology, University of MarylandCollege ParkUnited States
| | - Nao Rho
- Department of Biology, University of MarylandCollege ParkUnited States
| | - Padideh Ghorbani
- Department of Biology, University of MarylandCollege ParkUnited States
| | - Pouyan Rahmani
- Department of Ophthalmology & Visual Science, Yale UniversityNew HavenUnited States
| | - Na Young Jun
- Department of Ophthalmology & Visual Science, Yale UniversityNew HavenUnited States
| | - Hae-Lim Lee
- Department of Cellular & Molecular Physiology, Yale UniversityNew HavenUnited States
| | - In-Jung Kim
- Department of Ophthalmology & Visual Science, Yale UniversityNew HavenUnited States
| | - Kevin L Briggman
- Circuit Dynamics and Connectivity Unit, National Institute of Neurological Disorders and Stroke, National Institutes of HealthBethesdaUnited States
| | - Jonathan B Demb
- Department of Ophthalmology & Visual Science, Yale UniversityNew HavenUnited States
- Department of Cellular & Molecular Physiology, Yale UniversityNew HavenUnited States
- Department of Neuroscience, Yale UniversityNew HavenUnited States
| | - Joshua H Singer
- Department of Biology, University of MarylandCollege ParkUnited States
| |
Collapse
|
21
|
Hasan N, Pangeni G, Ray TA, Fransen KM, Noel J, Borghuis BG, McCall MA, Gregg RG. LRIT3 is Required for Nyctalopin Expression and Normal ON and OFF Pathway Signaling in the Retina. eNeuro 2020; 7:ENEURO.0002-20.2020. [PMID: 31959619 PMCID: PMC7031853 DOI: 10.1523/eneuro.0002-20.2020] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2019] [Accepted: 01/05/2020] [Indexed: 12/20/2022] Open
Abstract
The first retinal synapse, photoreceptor→bipolar cell (BC), is both anatomically and functionally complex. Within the same synaptic region, a change in presynaptic glutamate release is sensed by both ON BCs (DBCs) via the metabotropic glutamate receptor 6 (mGluR6), and OFF BCs (HBCs) via ionotropic glutamate receptors to establish parallel signaling pathways that preferentially encode light increments (ON) or decrements (OFF), respectively. The synaptic structural organization of ON and OFF-type BCs at the photoreceptor terminal differs. DBCs make an invaginating synapse that contains a diverse but incompletely understood complex of interacting proteins (signalplex). HBCs make primarily flat contacts that contain an apparent different set of proteins that is equally uncharacterized. LRIT3 is a synaptic protein known to be essential for ON pathway visual function. In both male and female mice, we demonstrate that LRIT3 interacts with and is required for expression of nyctalopin, and thus TRPM1 at all DBC dendritic tips, but DBC signalplex components are not required for LRIT3 expression. Using whole-cell and multielectrode array (MEA) electrophysiology and glutamate imaging, we demonstrate that the loss of LRIT3 impacts both ON and OFF signaling pathway function. Without LRIT3, excitatory input to type 1 BCs is reduced, as are the visually evoked responses of many OFF retinal ganglion cells (RGCs). We conclude that the absence of LRIT3 expression disrupts excitatory input to OFF BCs and, thus disrupts the normal function of OFF RGCs.
Collapse
Affiliation(s)
- Nazarul Hasan
- Department of Biochemistry and Molecular Genetics, University of Louisville, Louisville, KY 40292
| | - Gobinda Pangeni
- Department of Ophthalmology and Visual Sciences, University of Louisville, Louisville, KY 40292
| | - Thomas A Ray
- Department of Biochemistry and Molecular Genetics, University of Louisville, Louisville, KY 40292
| | - Kathryn M Fransen
- Department of Ophthalmology and Visual Sciences, University of Louisville, Louisville, KY 40292
| | - Jennifer Noel
- Department of Ophthalmology and Visual Sciences, University of Louisville, Louisville, KY 40292
- Department of Anatomical Sciences and Neurobiology, University of Louisville, Louisville, KY 40292
| | - Bart G Borghuis
- Department of Anatomical Sciences and Neurobiology, University of Louisville, Louisville, KY 40292
| | - Maureen A McCall
- Department of Ophthalmology and Visual Sciences, University of Louisville, Louisville, KY 40292
- Department of Anatomical Sciences and Neurobiology, University of Louisville, Louisville, KY 40292
| | - Ronald G Gregg
- Department of Biochemistry and Molecular Genetics, University of Louisville, Louisville, KY 40292
- Department of Ophthalmology and Visual Sciences, University of Louisville, Louisville, KY 40292
| |
Collapse
|
22
|
Grünert U, Martin PR. Cell types and cell circuits in human and non-human primate retina. Prog Retin Eye Res 2020; 78:100844. [PMID: 32032773 DOI: 10.1016/j.preteyeres.2020.100844] [Citation(s) in RCA: 76] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2019] [Revised: 01/28/2020] [Accepted: 01/31/2020] [Indexed: 12/12/2022]
Abstract
This review summarizes our current knowledge of primate including human retina focusing on bipolar, amacrine and ganglion cells and their connectivity. We have two main motivations in writing. Firstly, recent progress in non-invasive imaging methods to study retinal diseases mean that better understanding of the primate retina is becoming an important goal both for basic and for clinical sciences. Secondly, genetically modified mice are increasingly used as animal models for human retinal diseases. Thus, it is important to understand to which extent the retinas of primates and rodents are comparable. We first compare cell populations in primate and rodent retinas, with emphasis on how the fovea (despite its small size) dominates the neural landscape of primate retina. We next summarise what is known, and what is not known, about the postreceptoral neurone populations in primate retina. The inventories of bipolar and ganglion cells in primates are now nearing completion, comprising ~12 types of bipolar cell and at least 17 types of ganglion cell. Primate ganglion cells show clear differences in dendritic field size across the retina, and their morphology differs clearly from that of mouse retinal ganglion cells. Compared to bipolar and ganglion cells, amacrine cells show even higher morphological diversity: they could comprise over 40 types. Many amacrine types appear conserved between primates and mice, but functions of only a few types are understood in any primate or non-primate retina. Amacrine cells appear as the final frontier for retinal research in monkeys and mice alike.
Collapse
Affiliation(s)
- Ulrike Grünert
- The University of Sydney, Save Sight Institute, Faculty of Medicine and Health, Sydney, NSW, 2000, Australia; Australian Research Council Centre of Excellence for Integrative Brain Function, Sydney Node, The University of Sydney, Sydney, NSW, 2000, Australia.
| | - Paul R Martin
- The University of Sydney, Save Sight Institute, Faculty of Medicine and Health, Sydney, NSW, 2000, Australia; Australian Research Council Centre of Excellence for Integrative Brain Function, Sydney Node, The University of Sydney, Sydney, NSW, 2000, Australia
| |
Collapse
|
23
|
Ketkar MD, Sporar K, Gür B, Ramos-Traslosheros G, Seifert M, Silies M. Luminance Information Is Required for the Accurate Estimation of Contrast in Rapidly Changing Visual Contexts. Curr Biol 2020; 30:657-669.e4. [PMID: 32008904 DOI: 10.1016/j.cub.2019.12.038] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2019] [Revised: 11/01/2019] [Accepted: 12/11/2019] [Indexed: 11/28/2022]
Abstract
Visual perception scales with changes in the visual stimulus, or contrast, irrespective of background illumination. However, visual perception is challenged when adaptation is not fast enough to deal with sudden declines in overall illumination, for example, when gaze follows a moving object from bright sunlight into a shaded area. Here, we show that the visual system of the fly employs a solution by propagating a corrective luminance-sensitive signal. We use in vivo 2-photon imaging and behavioral analyses to demonstrate that distinct OFF-pathway inputs encode contrast and luminance. Predictions of contrast-sensitive neuronal responses show that contrast information alone cannot explain behavioral responses in sudden dim light. The luminance-sensitive pathway via the L3 neuron is required for visual processing in such rapidly changing light conditions, ensuring contrast constancy when pure contrast sensitivity underestimates a stimulus. Thus, retaining a peripheral feature, luminance, in visual processing is required for robust behavioral responses.
Collapse
Affiliation(s)
- Madhura D Ketkar
- Institute of Developmental Biology and Neurobiology, Johannes Gutenberg-Universität Mainz, Hanns-Dieter-Hüsch-Weg 15, Mainz 55128, Germany; European Neuroscience Institute Göttingen, a Joint Initiative of the University Medical Center Göttingen and the Max Planck Society, Grisebachstr. 5, Göttingen 37077, Germany; International Max Planck Research School and Göttingen Graduate School for Neurosciences, Biophysics, and Molecular Biosciences (GGNB) at the University of Göttingen, Justus-von-Liebig-Weg 11, Göttingen 37077, Germany
| | - Katja Sporar
- Institute of Developmental Biology and Neurobiology, Johannes Gutenberg-Universität Mainz, Hanns-Dieter-Hüsch-Weg 15, Mainz 55128, Germany; European Neuroscience Institute Göttingen, a Joint Initiative of the University Medical Center Göttingen and the Max Planck Society, Grisebachstr. 5, Göttingen 37077, Germany; International Max Planck Research School and Göttingen Graduate School for Neurosciences, Biophysics, and Molecular Biosciences (GGNB) at the University of Göttingen, Justus-von-Liebig-Weg 11, Göttingen 37077, Germany
| | - Burak Gür
- Institute of Developmental Biology and Neurobiology, Johannes Gutenberg-Universität Mainz, Hanns-Dieter-Hüsch-Weg 15, Mainz 55128, Germany; European Neuroscience Institute Göttingen, a Joint Initiative of the University Medical Center Göttingen and the Max Planck Society, Grisebachstr. 5, Göttingen 37077, Germany; International Max Planck Research School and Göttingen Graduate School for Neurosciences, Biophysics, and Molecular Biosciences (GGNB) at the University of Göttingen, Justus-von-Liebig-Weg 11, Göttingen 37077, Germany
| | - Giordano Ramos-Traslosheros
- Institute of Developmental Biology and Neurobiology, Johannes Gutenberg-Universität Mainz, Hanns-Dieter-Hüsch-Weg 15, Mainz 55128, Germany; European Neuroscience Institute Göttingen, a Joint Initiative of the University Medical Center Göttingen and the Max Planck Society, Grisebachstr. 5, Göttingen 37077, Germany; International Max Planck Research School and Göttingen Graduate School for Neurosciences, Biophysics, and Molecular Biosciences (GGNB) at the University of Göttingen, Justus-von-Liebig-Weg 11, Göttingen 37077, Germany
| | - Marvin Seifert
- European Neuroscience Institute Göttingen, a Joint Initiative of the University Medical Center Göttingen and the Max Planck Society, Grisebachstr. 5, Göttingen 37077, Germany
| | - Marion Silies
- Institute of Developmental Biology and Neurobiology, Johannes Gutenberg-Universität Mainz, Hanns-Dieter-Hüsch-Weg 15, Mainz 55128, Germany; European Neuroscience Institute Göttingen, a Joint Initiative of the University Medical Center Göttingen and the Max Planck Society, Grisebachstr. 5, Göttingen 37077, Germany.
| |
Collapse
|
24
|
Van Hook MJ, Nawy S, Thoreson WB. Voltage- and calcium-gated ion channels of neurons in the vertebrate retina. Prog Retin Eye Res 2019; 72:100760. [PMID: 31078724 PMCID: PMC6739185 DOI: 10.1016/j.preteyeres.2019.05.001] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2019] [Revised: 04/25/2019] [Accepted: 05/01/2019] [Indexed: 02/06/2023]
Abstract
In this review, we summarize studies investigating the types and distribution of voltage- and calcium-gated ion channels in the different classes of retinal neurons: rods, cones, horizontal cells, bipolar cells, amacrine cells, interplexiform cells, and ganglion cells. We discuss differences among cell subtypes within these major cell classes, as well as differences among species, and consider how different ion channels shape the responses of different neurons. For example, even though second-order bipolar and horizontal cells do not typically generate fast sodium-dependent action potentials, many of these cells nevertheless possess fast sodium currents that can enhance their kinetic response capabilities. Ca2+ channel activity can also shape response kinetics as well as regulating synaptic release. The L-type Ca2+ channel subtype, CaV1.4, expressed in photoreceptor cells exhibits specific properties matching the particular needs of these cells such as limited inactivation which allows sustained channel activity and maintained synaptic release in darkness. The particular properties of K+ and Cl- channels in different retinal neurons shape resting membrane potentials, response kinetics and spiking behavior. A remaining challenge is to characterize the specific distributions of ion channels in the more than 100 individual cell types that have been identified in the retina and to describe how these particular ion channels sculpt neuronal responses to assist in the processing of visual information by the retina.
Collapse
Affiliation(s)
- Matthew J Van Hook
- Truhlsen Eye Institute, Department of Ophthalmology & Visual Sciences, University of Nebraska Medical Center, Omaha, NE, USA
| | - Scott Nawy
- Truhlsen Eye Institute, Department of Ophthalmology & Visual Sciences, University of Nebraska Medical Center, Omaha, NE, USA; Department Pharmacology & Experimental Neuroscience(2), University of Nebraska Medical Center, Omaha, NE, USA
| | - Wallace B Thoreson
- Truhlsen Eye Institute, Department of Ophthalmology & Visual Sciences, University of Nebraska Medical Center, Omaha, NE, USA; Department Pharmacology & Experimental Neuroscience(2), University of Nebraska Medical Center, Omaha, NE, USA.
| |
Collapse
|
25
|
Thoreson WB, Dacey DM. Diverse Cell Types, Circuits, and Mechanisms for Color Vision in the Vertebrate Retina. Physiol Rev 2019; 99:1527-1573. [PMID: 31140374 PMCID: PMC6689740 DOI: 10.1152/physrev.00027.2018] [Citation(s) in RCA: 63] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2018] [Revised: 03/27/2019] [Accepted: 04/02/2019] [Indexed: 01/13/2023] Open
Abstract
Synaptic interactions to extract information about wavelength, and thus color, begin in the vertebrate retina with three classes of light-sensitive cells: rod photoreceptors at low light levels, multiple types of cone photoreceptors that vary in spectral sensitivity, and intrinsically photosensitive ganglion cells that contain the photopigment melanopsin. When isolated from its neighbors, a photoreceptor confounds photon flux with wavelength and so by itself provides no information about color. The retina has evolved elaborate color opponent circuitry for extracting wavelength information by comparing the activities of different photoreceptor types broadly tuned to different parts of the visible spectrum. We review studies concerning the circuit mechanisms mediating opponent interactions in a range of species, from tetrachromatic fish with diverse color opponent cell types to common dichromatic mammals where cone opponency is restricted to a subset of specialized circuits. Distinct among mammals, primates have reinvented trichromatic color vision using novel strategies to incorporate evolution of an additional photopigment gene into the foveal structure and circuitry that supports high-resolution vision. Color vision is absent at scotopic light levels when only rods are active, but rods interact with cone signals to influence color perception at mesopic light levels. Recent evidence suggests melanopsin-mediated signals, which have been identified as a substrate for setting circadian rhythms, may also influence color perception. We consider circuits that may mediate these interactions. While cone opponency is a relatively simple neural computation, it has been implemented in vertebrates by diverse neural mechanisms that are not yet fully understood.
Collapse
Affiliation(s)
- Wallace B Thoreson
- Department of Ophthalmology and Visual Sciences, Truhlsen Eye Institute, University of Nebraska Medical Center , Omaha, Nebraska ; and Department of Biological Structure, Washington National Primate Research Center, University of Washington , Seattle, Washington
| | - Dennis M Dacey
- Department of Ophthalmology and Visual Sciences, Truhlsen Eye Institute, University of Nebraska Medical Center , Omaha, Nebraska ; and Department of Biological Structure, Washington National Primate Research Center, University of Washington , Seattle, Washington
| |
Collapse
|
26
|
Passos ADCF, Herculano AM, Oliveira KRHM, de Lima SMA, Rocha FAF, Freitas HR, da Silva Sampaio L, Figueiredo DP, da Costa Calaza K, de Melo Reis RA, do Nascimento JLM. Regulation of the Serotonergic System by Kainate in the Avian Retina. Cell Mol Neurobiol 2019; 39:1039-1049. [PMID: 31197744 DOI: 10.1007/s10571-019-00701-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2019] [Accepted: 06/07/2019] [Indexed: 12/20/2022]
Abstract
Serotonin (5-HT) has been recognized as a neurotransmitter in the vertebrate retina, restricted mainly to amacrine and bipolar cells. It is involved with synaptic processing and possibly as a mitogenic factor. We confirm that chick retina amacrine and bipolar cells are, respectively, heavily and faintly immunolabeled for 5-HT. Amacrine serotonergic cells also co-express tyrosine hydroxylase (TH), a marker of dopaminergic cells in the retina. Previous reports demonstrated that serotonin transport can be modulated by neurotransmitter receptor activation. As 5-HT is diffusely released as a neuromodulator and co-localized with other transmitters, we evaluated if 5-HT uptake or release is modulated by several mediators in the avian retina. The role of different glutamate receptors on serotonin transport and release in vitro and in vivo was also studied. We show that L-glutamate induces an inhibitory effect on [3H]5-HT uptake and this effect was specific to kainate receptor activation. Kainate-induced decrease in [3H]5-HT uptake was blocked by CNQX, an AMPA/kainate receptor antagonist, but not by MK-801, a NMDA receptor antagonist. [3H]5-HT uptake was not observed in the presence of AMPA, thus suggesting that the decrease in serotonin uptake is mediated by kainate. 5-HT (10-50 μM) had no intrinsic activity in raising intracellular Ca2+, but addition of 10 μM 5-HT decreased Ca2+ shifts induced by KCl in retinal neurons. Moreover, kainate decreased the number of bipolar and amacrine cells labeled to serotonin in chick retina. In conclusion, our data suggest a highly selective effect of kainate receptors in the regulation of serotonin functions in the retinal cells.
Collapse
Affiliation(s)
- Adelaide da Conceição Fonseca Passos
- Laboratório de Neuroquímica Molecular e Celular, Instituto de Ciências Biológicas, Universidade Federal do Pará, Campus Universitário do Guamá, Rua Augusto Correa 01, Belém-PA, 66075-110, Brazil
| | - Anderson Manoel Herculano
- Laboratório de Neuroquímica Molecular e Celular, Instituto de Ciências Biológicas, Universidade Federal do Pará, Campus Universitário do Guamá, Rua Augusto Correa 01, Belém-PA, 66075-110, Brazil
| | - Karen R H M Oliveira
- Laboratório de Neuroquímica Molecular e Celular, Instituto de Ciências Biológicas, Universidade Federal do Pará, Campus Universitário do Guamá, Rua Augusto Correa 01, Belém-PA, 66075-110, Brazil
| | - Silene Maria A de Lima
- Lab de Neurobiologia, Instituto de Ciências Biológicas, Universidade Federal do Pará, Belém-PA, Brazil
| | - Fernando A F Rocha
- Lab de Neurobiologia, Instituto de Ciências Biológicas, Universidade Federal do Pará, Belém-PA, Brazil
| | - Hércules Rezende Freitas
- Laboratório de Neuroquímica, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio De Janeiro-RJ, Brazil.,Escola de Ciências da Saúde, Centro Universitário IBMR, Rio De Janeiro-RJ, Brazil
| | - Luzia da Silva Sampaio
- Laboratório de Neuroquímica, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio De Janeiro-RJ, Brazil
| | - Danniel Pereira Figueiredo
- Laboratório de Neuroquímica, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio De Janeiro-RJ, Brazil
| | - Karin da Costa Calaza
- Lab Neurobiologia da Retina, Programa de Pós-graduação em Neurociências, Universidade Federal Fluminense, Rio De Janeiro-RJ, Brazil
| | - Ricardo Augusto de Melo Reis
- Laboratório de Neuroquímica, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio De Janeiro-RJ, Brazil
| | - José Luiz Martins do Nascimento
- Laboratório de Neuroquímica Molecular e Celular, Instituto de Ciências Biológicas, Universidade Federal do Pará, Campus Universitário do Guamá, Rua Augusto Correa 01, Belém-PA, 66075-110, Brazil.
| |
Collapse
|
27
|
Dürst CD, Wiegert JS, Helassa N, Kerruth S, Coates C, Schulze C, Geeves MA, Török K, Oertner TG. High-speed imaging of glutamate release with genetically encoded sensors. Nat Protoc 2019; 14:1401-1424. [PMID: 30988508 PMCID: PMC6751072 DOI: 10.1038/s41596-019-0143-9] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2018] [Accepted: 01/22/2019] [Indexed: 11/08/2022]
Abstract
The strength of an excitatory synapse depends on its ability to release glutamate and on the density of postsynaptic receptors. Genetically encoded glutamate indicators (GEGIs) allow eavesdropping on synaptic transmission at the level of cleft glutamate to investigate properties of the release machinery in detail. Based on the sensor iGluSnFR, we recently developed accelerated versions of GEGIs that allow investigation of synaptic release during 100-Hz trains. Here, we describe the detailed procedures for design and characterization of fast iGluSnFR variants in vitro, transfection of pyramidal cells in organotypic hippocampal cultures, and imaging of evoked glutamate transients with two-photon laser-scanning microscopy. As the released glutamate spreads from a point source-the fusing vesicle-it is possible to localize the vesicle fusion site with a precision exceeding the optical resolution of the microscope. By using a spiral scan path, the temporal resolution can be increased to 1 kHz to capture the peak amplitude of fast iGluSnFR transients. The typical time frame for these experiments is 30 min per synapse.
Collapse
Affiliation(s)
- Céline D Dürst
- Institute for Synaptic Physiology, Center for Molecular Neurobiology Hamburg, Hamburg, Germany
| | - J Simon Wiegert
- Institute for Synaptic Physiology, Center for Molecular Neurobiology Hamburg, Hamburg, Germany
- Research Group Synaptic Wiring and Information Processing, Center for Molecular Neurobiology Hamburg, Hamburg, Germany
| | - Nordine Helassa
- Molecular and Clinical Sciences Research Institute, St George's, University of London, London, UK
- Department of Cellular and Molecular Physiology, Institute of Translational Medicine, University of Liverpool, Liverpool, UK
| | - Silke Kerruth
- Molecular and Clinical Sciences Research Institute, St George's, University of London, London, UK
- Department of Biophysical Chemistry, J. Heyrovský Institute of Physical Chemistry, Prague, Czech Republic
| | - Catherine Coates
- Molecular and Clinical Sciences Research Institute, St George's, University of London, London, UK
| | - Christian Schulze
- Institute for Synaptic Physiology, Center for Molecular Neurobiology Hamburg, Hamburg, Germany
| | | | - Katalin Török
- Molecular and Clinical Sciences Research Institute, St George's, University of London, London, UK
| | - Thomas G Oertner
- Institute for Synaptic Physiology, Center for Molecular Neurobiology Hamburg, Hamburg, Germany.
| |
Collapse
|
28
|
Tiriac A, Smith BE, Feller MB. Light Prior to Eye Opening Promotes Retinal Waves and Eye-Specific Segregation. Neuron 2018; 100:1059-1065.e4. [PMID: 30392793 DOI: 10.1016/j.neuron.2018.10.011] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2018] [Revised: 08/24/2018] [Accepted: 10/05/2018] [Indexed: 11/16/2022]
Abstract
Retinal waves are bursts of correlated activity that occur prior to eye opening and provide a critical source of activity that drives the refinement of retinofugal projections. Retinal waves are thought to be initiated spontaneously with their spatiotemporal features dictated by immature neural circuits. Here we demonstrate that, during the second postnatal week in mice, changes in light intensity dictate where and when a subset of retinal waves are triggered via activation of conventional photoreceptors. Propagation properties of triggered waves are indistinguishable from spontaneous waves, indicating that they are activating the same retinal circuits. Using whole-brain imaging techniques, we demonstrate that light deprivation prior to eye opening diminishes eye-specific segregation of the retinal projections to the dorsolateral geniculate nucleus of the thalamus, but not other retinal targets. These data indicate that light that passes through the closed eyelids plays a critical role in the development of the image-forming visual system.
Collapse
Affiliation(s)
- Alexandre Tiriac
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Benjamin E Smith
- School of Optometry, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Marla B Feller
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA; Helen Wills Neuroscience Institute, University of California, Berkeley, Berkeley, CA, 94720, USA.
| |
Collapse
|
29
|
Yang CY, Tsai D, Guo T, Dokos S, Suaning GJ, Morley JW, Lovell NH. Differential electrical responses in retinal ganglion cell subtypes: effects of synaptic blockade and stimulating electrode location. J Neural Eng 2018; 15:046020. [PMID: 29737971 DOI: 10.1088/1741-2552/aac315] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
OBJECTIVE Visual prostheses have shown promising results in restoring visual perception to blind patients. The ability to differentially activate retinal ganglion cell (RGC) subtypes could further improve the efficacy of these medical devices. APPROACH Using whole-cell patch clamp, we investigated membrane potential differences between ON and OFF RGCs in the mouse retina when their synaptic inputs were blocked by synaptic blockers, and examined the differences in stimulation thresholds under such conditions. By injecting intracellular current, we further confirmed the relationship between RGC stimulation thresholds and resting membrane potentials (RMPs). In addition, we investigated the effects of stimulating electrode location on the differences in stimulation thresholds between ON and OFF RGCs. MAIN RESULTS With synaptic blockade, ON RGCs became significantly more hyperpolarized (from -61.8 ± 1.4 mV to -70.8 ± 1.6 mV), while OFF RGCs depolarized slightly (from -60.5 ± 0.7 mV to -58.6 ± 0.9 mV). RGC stimulation thresholds were negatively correlated with their RMPs (Pearson r value: -0.5154; p-value: 0.0042). Thus, depriving ON RGCs of synaptic inputs significantly increased their thresholds (from 14.7 ± 1.3 µA to 22.3 ± 2.1 µA) over those of OFF RGCs (from 13.2 ± 0.7 µA to 13.1 ± 1.1 µA). However, with control solution, ON and OFF RGC stimulation thresholds were not significantly different. Finally, placement of the stimulating electrode away from the axon enhanced differences in stimulation thresholds between ON and OFF RGCs, facilitating preferential activation of OFF RGCs. SIGNIFICANCE Since ON and OFF RGCs have antagonistic responses to natural light, achieving differential RGC activation could convey more natural visual information, leading to better visual prosthesis outcomes.
Collapse
Affiliation(s)
- Chih Yu Yang
- Graduate School of Biomedical Engineering, UNSW, Sydney, NSW 2052, Australia
| | | | | | | | | | | | | |
Collapse
|
30
|
Park SJH, Pottackal J, Ke JB, Jun NY, Rahmani P, Kim IJ, Singer JH, Demb JB. Convergence and Divergence of CRH Amacrine Cells in Mouse Retinal Circuitry. J Neurosci 2018; 38:3753-3766. [PMID: 29572434 PMCID: PMC5895998 DOI: 10.1523/jneurosci.2518-17.2018] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2017] [Revised: 03/01/2018] [Accepted: 03/07/2018] [Indexed: 11/21/2022] Open
Abstract
Inhibitory interneurons sculpt the outputs of excitatory circuits to expand the dynamic range of information processing. In mammalian retina, >30 types of amacrine cells provide lateral inhibition to vertical, excitatory bipolar cell circuits, but functional roles for only a few amacrine cells are well established. Here, we elucidate the function of corticotropin-releasing hormone (CRH)-expressing amacrine cells labeled in Cre-transgenic mice of either sex. CRH cells costratify with the ON alpha ganglion cell, a neuron highly sensitive to positive contrast. Electrophysiological and optogenetic analyses demonstrate that two CRH types (CRH-1 and CRH-3) make GABAergic synapses with ON alpha cells. CRH-1 cells signal via graded membrane potential changes, whereas CRH-3 cells fire action potentials. Both types show sustained ON-type responses to positive contrast over a range of stimulus conditions. Optogenetic control of transmission at CRH-1 synapses demonstrates that these synapses are tuned to low temporal frequencies, maintaining GABA release during fast hyperpolarizations during brief periods of negative contrast. CRH amacrine cell output is suppressed by prolonged negative contrast, when ON alpha ganglion cells continue to receive inhibitory input from converging OFF-pathway amacrine cells; the converging ON- and OFF-pathway inhibition balances tonic excitatory drive to ON alpha cells. Previously, it was demonstrated that CRH-1 cells inhibit firing by suppressed-by-contrast (SbC) ganglion cells during positive contrast. Therefore, divergent outputs of CRH-1 cells inhibit two ganglion cell types with opposite responses to positive contrast. The opposing responses of ON alpha and SbC ganglion cells are explained by differing excitation/inhibition balance in the two circuits.SIGNIFICANCE STATEMENT A goal of neuroscience research is to explain the function of neural circuits at the level of specific cell types. Here, we studied the function of specific types of inhibitory interneurons, corticotropin-releasing hormone (CRH) amacrine cells, in the mouse retina. Genetic tools were used to identify and manipulate CRH cells, which make GABAergic synapses with a well studied ganglion cell type, the ON alpha cell. CRH cells converge with other types of amacrine cells to tonically inhibit ON alpha cells and balance their high level of excitation. CRH cells diverge to different types of ganglion cell, the unique properties of which depend on their balance of excitation and inhibition.
Collapse
Affiliation(s)
| | | | - Jiang-Bin Ke
- Department of Biology, University of Maryland, College Park, Maryland 20742
| | | | | | - In-Jung Kim
- Department of Ophthalmology and Visual Science
- Interdepartmental Neuroscience Program
- Department of Neuroscience
| | - Joshua H Singer
- Department of Biology, University of Maryland, College Park, Maryland 20742
| | - Jonathan B Demb
- Department of Ophthalmology and Visual Science,
- Interdepartmental Neuroscience Program
- Department of Cellular and Molecular Physiology, Yale University, New Haven, Connecticut 06511, and
| |
Collapse
|
31
|
Clark DA, Demb JB. Parallel Computations in Insect and Mammalian Visual Motion Processing. Curr Biol 2017; 26:R1062-R1072. [PMID: 27780048 DOI: 10.1016/j.cub.2016.08.003] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Sensory systems use receptors to extract information from the environment and neural circuits to perform subsequent computations. These computations may be described as algorithms composed of sequential mathematical operations. Comparing these operations across taxa reveals how different neural circuits have evolved to solve the same problem, even when using different mechanisms to implement the underlying math. In this review, we compare how insect and mammalian neural circuits have solved the problem of motion estimation, focusing on the fruit fly Drosophila and the mouse retina. Although the two systems implement computations with grossly different anatomy and molecular mechanisms, the underlying circuits transform light into motion signals with strikingly similar processing steps. These similarities run from photoreceptor gain control and spatiotemporal tuning to ON and OFF pathway structures, motion detection, and computed motion signals. The parallels between the two systems suggest that a limited set of algorithms for estimating motion satisfies both the needs of sighted creatures and the constraints imposed on them by metabolism, anatomy, and the structure and regularities of the visual world.
Collapse
Affiliation(s)
- Damon A Clark
- Department of Molecular, Cellular, and Developmental Biology and Department of Physics, Yale University, New Haven, CT 06511, USA.
| | - Jonathan B Demb
- Department of Ophthalmology and Visual Science and Department of Cellular and Molecular Physiology, Yale University, New Haven, CT 06511, USA.
| |
Collapse
|
32
|
Opere CA, Heruye S, Njie-Mbye YF, Ohia SE, Sharif NA. Regulation of Excitatory Amino Acid Transmission in the Retina: Studies on Neuroprotection. J Ocul Pharmacol Ther 2017; 34:107-118. [PMID: 29267132 DOI: 10.1089/jop.2017.0085] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Excitotoxicity occurs in neurons due to the accumulation of excitatory amino acids such as glutamate in the synaptic and extrasynaptic locations. In the retina, excessive glutamate concentrations trigger a neurotoxic cascade involving several mechanisms, including the elevation of intracellular calcium (Ca2+) and the activation of α-amino-3-hydroxy 5-methyl-4-iso-xazole-propionic acid/kainate (AMPA/KA) and N-methyl-d-aspartate (NMDA) receptors leading to retinal degeneration. Both ionotropic glutamate receptors (iGluRs) and metabotropic glutamate receptors (mGluRs) are present in the mammalian retina. Indeed, due to the abundant expression of GluRs, the mammalian retina is highly susceptible to excitotoxic neurodegeneration. Excitotoxicity has been postulated to present a common downstream mechanism for several stimuli, including hypoglycemia, hypoxia, ischemia, and chronic neurodegenerative diseases. Experimental approaches to the study of neuroprotection in the retina have utilized insults that trigger hypoxia, hypoglycemia, or excitotoxicity. Using these experimental approaches, the neuroprotective potential of GluR agents, including the NMDA receptor modulators (MK801, ifenprodil, memantine); AMPA/KA receptor antagonist (CNQX); Group II and III mGluR agonists (LY354740, quisqualate); and Ca2+-channel blockers (diltiazem, lomerizine, verapamil, ω-conotoxin), and others (pituitary adenylate cyclase activating polypeptide, neuropeptide Y, acetylcholine receptor agonists) have been elucidated. In addition to corroborating the exocytotic role of excitatory amino acids in retinal degeneration, these studies affirm that multiple mechanism/s contribute to the prevention of damage caused by excitotoxicity in the retina. Therefore, it is feasible that several pathways are involved in protecting the retina from toxic insults in ocular neurodegenerative conditions such as glaucoma and retinal ischemia. Furthermore, these experimental models are viable tools for evaluating therapeutic candidates in ocular neuropathies.
Collapse
Affiliation(s)
- Catherine A Opere
- 1 Department of Pharmacy Sciences, School of Pharmacy and Health Professions, Creighton University , Omaha, Nebraska
| | - Segewkal Heruye
- 1 Department of Pharmacy Sciences, School of Pharmacy and Health Professions, Creighton University , Omaha, Nebraska
| | - Ya-Fatou Njie-Mbye
- 2 Department of Environmental and Pharmaceutical Sciences, College of Pharmacy and Health Sciences, Texas Southern University , Houston, Texas
| | - Sunny E Ohia
- 2 Department of Environmental and Pharmaceutical Sciences, College of Pharmacy and Health Sciences, Texas Southern University , Houston, Texas
| | - Najam A Sharif
- 2 Department of Environmental and Pharmaceutical Sciences, College of Pharmacy and Health Sciences, Texas Southern University , Houston, Texas.,3 Santen Incorporated , Emeryville, California
| |
Collapse
|
33
|
Simmons AB, Bloomsburg SJ, Sukeena JM, Miller CJ, Ortega-Burgos Y, Borghuis BG, Fuerst PG. DSCAM-mediated control of dendritic and axonal arbor outgrowth enforces tiling and inhibits synaptic plasticity. Proc Natl Acad Sci U S A 2017; 114:E10224-E10233. [PMID: 29114051 PMCID: PMC5703318 DOI: 10.1073/pnas.1713548114] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Mature mammalian neurons have a limited ability to extend neurites and make new synaptic connections, but the mechanisms that inhibit such plasticity remain poorly understood. Here, we report that OFF-type retinal bipolar cells in mice are an exception to this rule, as they form new anatomical connections within their tiled dendritic fields well after retinal maturity. The Down syndrome cell-adhesion molecule (Dscam) confines these anatomical rearrangements within the normal tiled fields, as conditional deletion of the gene permits extension of dendrite and axon arbors beyond these borders. Dscam deletion in the mature retina results in expanded dendritic fields and increased cone photoreceptor contacts, demonstrating that DSCAM actively inhibits circuit-level plasticity. Electrophysiological recordings from Dscam-/- OFF bipolar cells showed enlarged visual receptive fields, demonstrating that expanded dendritic territories comprise functional synapses. Our results identify cell-adhesion molecule-mediated inhibition as a regulator of circuit-level neuronal plasticity in the adult retina.
Collapse
Affiliation(s)
- Aaron B Simmons
- Department of Biological Sciences, University of Idaho, Moscow, ID 83844
| | | | - Joshua M Sukeena
- Department of Biological Sciences, University of Idaho, Moscow, ID 83844
| | - Calvin J Miller
- Department of Biological Sciences, University of Idaho, Moscow, ID 83844
| | - Yohaniz Ortega-Burgos
- Department of Chemistry, University of Puerto Rico-Humacao, Humacao Puerto Rico, 00792
| | - Bart G Borghuis
- Department of Anatomical Sciences and Neurobiology, University of Louisville School of Medicine, Louisville, KY 40202;
| | - Peter G Fuerst
- Department of Biological Sciences, University of Idaho, Moscow, ID 83844;
- Washington-Wyoming-Alaska-Montana-Idaho Medical Education Program, University of Washington School of Medicine, Moscow, ID 83844
| |
Collapse
|
34
|
"Silent" NMDA Synapses Enhance Motion Sensitivity in a Mature Retinal Circuit. Neuron 2017; 96:1099-1111.e3. [PMID: 29107522 DOI: 10.1016/j.neuron.2017.09.058] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2016] [Revised: 06/09/2017] [Accepted: 09/28/2017] [Indexed: 12/30/2022]
Abstract
Retinal direction-selective ganglion cells (DSGCs) have the remarkable ability to encode motion over a wide range of contrasts, relying on well-coordinated excitation and inhibition (E/I). E/I is orchestrated by a diverse set of glutamatergic bipolar cells that drive DSGCs directly, as well as indirectly through feedforward GABAergic/cholinergic signals mediated by starburst amacrine cells. Determining how direction-selective responses are generated across varied stimulus conditions requires understanding how glutamate, acetylcholine, and GABA signals are precisely coordinated. Here, we use a combination of paired patch-clamp recordings, serial EM, and large-scale multi-electrode array recordings to show that a single high-sensitivity source of glutamate is processed differentially by starbursts via AMPA receptors and DSGCs via NMDA receptors. We further demonstrate how this novel synaptic arrangement enables DSGCs to encode direction robustly near threshold contrasts. Together, these results reveal a space-efficient synaptic circuit model for direction computations, in which "silent" NMDA receptors play critical roles.
Collapse
|
35
|
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.
Collapse
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
| |
Collapse
|
36
|
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] [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.
Collapse
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)
| |
Collapse
|
37
|
Contributions of Rod and Cone Pathways to Retinal Direction Selectivity Through Development. J Neurosci 2017; 36:9683-95. [PMID: 27629718 DOI: 10.1523/jneurosci.3824-15.2016] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2015] [Accepted: 07/28/2016] [Indexed: 11/21/2022] Open
Abstract
UNLABELLED Direction selectivity is a robust computation across a broad stimulus space that is mediated by activity of both rod and cone photoreceptors through the ON and OFF pathways. However, rods, S-cones, and M-cones activate the ON and OFF circuits via distinct pathways and the relative contribution of each to direction selectivity is unknown. Using a variety of stimulation paradigms, pharmacological agents, and knockout mice that lack rod transduction, we found that inputs from the ON pathway were critical for strong direction-selective (DS) tuning in the OFF pathway. For UV light stimulation, the ON pathway inputs to the OFF pathway originated with rod signaling, whereas for visible stimulation, the ON pathway inputs to the OFF pathway originated with both rod and M-cone signaling. Whole-cell voltage-clamp recordings revealed that blocking the ON pathway reduced directional tuning in the OFF pathway via a reduction in null-side inhibition, which is provided by OFF starburst amacrine cells (SACs). Consistent with this, our recordings from OFF SACs confirmed that signals originating in the ON pathway contribute to their excitation. Finally, we observed that, for UV stimulation, ON contributions to OFF DS tuning matured earlier than direct signaling via the OFF pathway. These data indicate that the retina uses multiple strategies for computing DS responses across different colors and stages of development. SIGNIFICANCE STATEMENT The retina uses parallel pathways to encode different features of the visual scene. In some cases, these distinct pathways converge on circuits that mediate a distinct computation. For example, rod and cone pathways enable direction-selective (DS) ganglion cells to encode motion over a wide range of light intensities. Here, we show that although direction selectivity is robust across light intensities, motion discrimination for OFF signals is dependent upon ON signaling. At eye opening, ON directional tuning is mature, whereas OFF DS tuning is significantly reduced due to a delayed maturation of S-cone to OFF cone bipolar signaling. These results provide evidence that the retina uses multiple strategies for computing DS responses across different stimulus conditions.
Collapse
|
38
|
Franke K, Baden T. General features of inhibition in the inner retina. J Physiol 2017; 595:5507-5515. [PMID: 28332227 PMCID: PMC5556161 DOI: 10.1113/jp273648] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2016] [Accepted: 02/08/2017] [Indexed: 11/08/2022] Open
Abstract
Visual processing starts in the retina. Within only two synaptic layers, a large number of parallel information channels emerge, each encoding a highly processed feature like edges or the direction of motion. Much of this functional diversity arises in the inner plexiform layer, where inhibitory amacrine cells modulate the excitatory signal of bipolar and ganglion cells. Studies investigating individual amacrine cell circuits like the starburst or A17 circuit have demonstrated that single types can possess specific morphological and functional adaptations to convey a particular function in one or a small number of inner retinal circuits. However, the interconnected and often stereotypical network formed by different types of amacrine cells across the inner plexiform layer prompts that they should be also involved in more general computations. In line with this notion, different recent studies systematically analysing inner retinal signalling at a population level provide evidence that general functions of the ensemble of amacrine cells across types are critical for establishing universal principles of retinal computation like parallel processing or motion anticipation. Combining recent advances in the development of indicators for imaging inhibition with large-scale morphological and genetic classifications will help to further our understanding of how single amacrine cell circuits act together to help decompose the visual scene into parallel information channels. In this review, we aim to summarise the current state-of-the-art in our understanding of how general features of amacrine cell inhibition lead to general features of computation.
Collapse
Affiliation(s)
- Katrin Franke
- Centre for Integrative NeuroscienceUniversity of TübingenGermany
- Institute for Ophthalmic ResearchTübingenGermany
- Bernstein Centre for Computational NeuroscienceTübingenGermany
| | - Tom Baden
- Institute for Ophthalmic ResearchTübingenGermany
- School of Life SciencesUniversity of SussexBrightonUK
| |
Collapse
|
39
|
Neuillé M, Cao Y, Caplette R, Guerrero-Given D, Thomas C, Kamasawa N, Sahel JA, Hamel CP, Audo I, Picaud S, Martemyanov KA, Zeitz C. LRIT3 Differentially Affects Connectivity and Synaptic Transmission of Cones to ON- and OFF-Bipolar Cells. Invest Ophthalmol Vis Sci 2017; 58:1768-1778. [PMID: 28334377 PMCID: PMC5374884 DOI: 10.1167/iovs.16-20745] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Purpose Mutations in LRIT3 lead to complete congenital stationary night blindness (cCSNB). Using a cCSNB mouse model lacking Lrit3 (nob6), we recently have shown that LRIT3 has a role in the correct localization of TRPM1 (transient receptor potential melastatin 1) to the dendritic tips of ON-bipolar cells (BCs), contacting both rod and cone photoreceptors. Furthermore, postsynaptic clustering of other mGluR6 cascade components is selectively eliminated at the dendritic tips of cone ON-BCs. The purpose of this study was to further define the role of LRIT3 in structural and functional organization of cone synapses. Methods Exhaustive electroretinogram analysis was performed in a patient with LRIT3 mutations. Multielectrode array recordings were performed at the level of retinal ganglion cells in nob6 mice. Targeting of GluR1 and GluR5 at the dendritic tips of OFF-BCs in nob6 retinas was assessed by immunostaining and confocal microscopy. The ultrastructure of photoreceptor synapses was evaluated by electron microscopy in nob6 mice. Results The patient with LRIT3 mutations had a selective ON-BC dysfunction with relatively preserved OFF-BC responses. In nob6 mice, complete lack of ON-pathway function with robust, yet altered signaling processing in OFF-pathways was detected. Consistent with these observations, molecules essential for the OFF-BC signaling were normally targeted to the synapse. Finally, synaptic contacts made by ON-BC but not OFF-BC neurons with the cone pedicles were disorganized without ultrastructural alterations in cone terminals, horizontal cell processes, or synaptic ribbons. Conclusions These results suggest that LRIT3 is likely involved in coordination of the transsynaptic communication between cones and ON-BCs during synapse formation and function.
Collapse
Affiliation(s)
- Marion Neuillé
- Sorbonne Universités, UPMC Univ Paris 06, INSERM U968, CNRS UMR 7210, Institut de la Vision, Paris, France
| | - Yan Cao
- Department of Neuroscience, The Scripps Research Institute, Jupiter, Florida United States
| | - Romain Caplette
- Sorbonne Universités, UPMC Univ Paris 06, INSERM U968, CNRS UMR 7210, Institut de la Vision, Paris, France
| | | | - Connon Thomas
- Max Planck Florida Institute for Neuroscience, Jupiter, Florida United States
| | - Naomi Kamasawa
- Max Planck Florida Institute for Neuroscience, Jupiter, Florida United States
| | - José-Alain Sahel
- Sorbonne Universités, UPMC Univ Paris 06, INSERM U968, CNRS UMR 7210, Institut de la Vision, Paris, France 4CHNO des Quinze-Vingts, DHU Sight Restore, INSERM-DHOS CIC1423, Paris, France 5Institute of Ophthalmology, University College of London, London, United Kingdom 6Fondation Ophtalmologique Adolphe de Rothschild, Paris, France 8Department of Ophthalmology, The University of Pittsburgh School of Medicine, Pittsburgh, United States
| | - Christian P Hamel
- INSERM U583, Physiopathologie et thérapie des déficits sensoriels et moteurs, Institut des Neurosciences de Montpellier, Hôpital Saint-Eloi, Montpellier, France
| | - Isabelle Audo
- Sorbonne Universités, UPMC Univ Paris 06, INSERM U968, CNRS UMR 7210, Institut de la Vision, Paris, France 4CHNO des Quinze-Vingts, DHU Sight Restore, INSERM-DHOS CIC1423, Paris, France 5Institute of Ophthalmology, University College of London, London, United Kingdom
| | - Serge Picaud
- Sorbonne Universités, UPMC Univ Paris 06, INSERM U968, CNRS UMR 7210, Institut de la Vision, Paris, France
| | - Kirill A Martemyanov
- Department of Neuroscience, The Scripps Research Institute, Jupiter, Florida United States
| | - Christina Zeitz
- Sorbonne Universités, UPMC Univ Paris 06, INSERM U968, CNRS UMR 7210, Institut de la Vision, Paris, France
| |
Collapse
|
40
|
Dendritic stratification differs among retinal OFF bipolar cell types in the absence of rod photoreceptors. PLoS One 2017; 12:e0173455. [PMID: 28257490 PMCID: PMC5336283 DOI: 10.1371/journal.pone.0173455] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2016] [Accepted: 02/22/2017] [Indexed: 01/09/2023] Open
Abstract
Retinal OFF bipolar cells show distinct connectivity patterns with photoreceptors in the wild-type mouse retina. Some types are cone-specific while others penetrate further through the outer plexiform layer (OPL) to contact rods in addition to cones. To explore dendritic stratification of OFF bipolar cells in the absence of rods, we made use of the 'cone-full' Nrl-/- mouse retina in which all photoreceptor precursor cells commit to a cone fate including those which would have become rods in wild-type retinas. The dendritic distribution of OFF bipolar cell types was investigated by confocal and electron microscopic imaging of immunolabeled tissue sections. The cells' dendrites formed basal contacts with cone terminals and expressed the corresponding glutamate receptor subunits at those sites, indicating putative synapses. All of the four analyzed cell populations showed distinctive patterns of vertical dendritic invasion through the OPL. This disparate behavior of dendritic extension in an environment containing only cone terminals demonstrates type-dependent specificity for dendritic outgrowth in OFF bipolar cells: rod terminals are not required for inducing dendritic extension into distal areas of the OPL.
Collapse
|
41
|
Shekhar K, Lapan SW, Whitney IE, Tran NM, Macosko EZ, Kowalczyk M, Adiconis X, Levin JZ, Nemesh J, Goldman M, McCarroll SA, Cepko CL, Regev A, Sanes JR. Comprehensive Classification of Retinal Bipolar Neurons by Single-Cell Transcriptomics. Cell 2016; 166:1308-1323.e30. [PMID: 27565351 DOI: 10.1016/j.cell.2016.07.054] [Citation(s) in RCA: 721] [Impact Index Per Article: 90.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2016] [Revised: 06/10/2016] [Accepted: 07/28/2016] [Indexed: 12/15/2022]
Abstract
Patterns of gene expression can be used to characterize and classify neuronal types. It is challenging, however, to generate taxonomies that fulfill the essential criteria of being comprehensive, harmonizing with conventional classification schemes, and lacking superfluous subdivisions of genuine types. To address these challenges, we used massively parallel single-cell RNA profiling and optimized computational methods on a heterogeneous class of neurons, mouse retinal bipolar cells (BCs). From a population of ∼25,000 BCs, we derived a molecular classification that identified 15 types, including all types observed previously and two novel types, one of which has a non-canonical morphology and position. We validated the classification scheme and identified dozens of novel markers using methods that match molecular expression to cell morphology. This work provides a systematic methodology for achieving comprehensive molecular classification of neurons, identifies novel neuronal types, and uncovers transcriptional differences that distinguish types within a class.
Collapse
Affiliation(s)
- Karthik Shekhar
- Broad Institute of Harvard and MIT, Cambridge, MA 02142, USA
| | - Sylvain W Lapan
- Department of Genetics, Harvard Medical School, Boston, MA 02115, USA; Howard Hughes Medical Institute, Chevy Chase, MD 20815, USA
| | - Irene E Whitney
- Center for Brain Science and Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA 02130, USA
| | - Nicholas M Tran
- Center for Brain Science and Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA 02130, USA
| | - Evan Z Macosko
- Department of Genetics, Harvard Medical School, Boston, MA 02115, USA; Stanley Center for Psychiatric Research, Broad Institute of Harvard and MIT, Cambridge, MA 02142, USA; Program in Medical and Population Genetics, Broad Institute of Harvard and MIT, Cambridge, MA 02142, USA
| | | | - Xian Adiconis
- Broad Institute of Harvard and MIT, Cambridge, MA 02142, USA; Stanley Center for Psychiatric Research, Broad Institute of Harvard and MIT, Cambridge, MA 02142, USA
| | - Joshua Z Levin
- Broad Institute of Harvard and MIT, Cambridge, MA 02142, USA; Stanley Center for Psychiatric Research, Broad Institute of Harvard and MIT, Cambridge, MA 02142, USA
| | - James Nemesh
- Department of Genetics, Harvard Medical School, Boston, MA 02115, USA; Stanley Center for Psychiatric Research, Broad Institute of Harvard and MIT, Cambridge, MA 02142, USA; Program in Medical and Population Genetics, Broad Institute of Harvard and MIT, Cambridge, MA 02142, USA
| | - Melissa Goldman
- Department of Genetics, Harvard Medical School, Boston, MA 02115, USA; Stanley Center for Psychiatric Research, Broad Institute of Harvard and MIT, Cambridge, MA 02142, USA
| | - Steven A McCarroll
- Department of Genetics, Harvard Medical School, Boston, MA 02115, USA; Stanley Center for Psychiatric Research, Broad Institute of Harvard and MIT, Cambridge, MA 02142, USA; Program in Medical and Population Genetics, Broad Institute of Harvard and MIT, Cambridge, MA 02142, USA
| | - Constance L Cepko
- Department of Genetics, Harvard Medical School, Boston, MA 02115, USA; Department of Ophthalmology, Harvard Medical School, Boston, MA 02115, USA; Howard Hughes Medical Institute, Chevy Chase, MD 20815, USA.
| | - Aviv Regev
- Broad Institute of Harvard and MIT, Cambridge, MA 02142, USA; Howard Hughes Medical Institute, Chevy Chase, MD 20815, USA; Department of Biology and Koch Institute, MIT, Cambridge, MA 02139, USA.
| | - Joshua R Sanes
- Center for Brain Science and Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA 02130, USA.
| |
Collapse
|
42
|
MacDonald RB, Kashikar ND, Lagnado L, Harris WA. A Novel Tool to Measure Extracellular Glutamate in the Zebrafish Nervous System In Vivo. Zebrafish 2016; 14:284-286. [PMID: 28027028 PMCID: PMC5466054 DOI: 10.1089/zeb.2016.1385] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Glutamate is the major excitatory neurotransmitter in the brain. Its release and eventual recycling are key to rapid sustained neural activity. We have paired the gfap promoter region with the glutamate reporter molecule, iGluSnFR, to drive expression in glial cells throughout the nervous system. Tg(gfap:iGluSnFR) is expressed on the glial membrane of Müller glia cells in the retina, which rapidly respond to stimulation and the release of extracellular glutamate. As glial cells are associated with most, if not all, synapses, Tg(gfap:iGluSnFR) is a novel and exciting tool to measure neuronal activity and extracellular glutamate dynamics in many regions of the nervous system.
Collapse
Affiliation(s)
- Ryan B. MacDonald
- Department of Infection, Immunity and Cardiovascular Disease, Medical School and the Bateson Centre, University of Sheffield, Sheffield, United Kingdom
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, United Kingdom
| | - Nachiket D. Kashikar
- Sussex Neuroscience, School of Life Sciences, University of Sussex, Brighton, United Kingdom
| | - Leon Lagnado
- Sussex Neuroscience, School of Life Sciences, University of Sussex, Brighton, United Kingdom
| | - William A. Harris
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, United Kingdom
| |
Collapse
|
43
|
Electrophysiological fingerprints of OFF bipolar cells in rat retina. Sci Rep 2016; 6:30259. [PMID: 27457753 PMCID: PMC4960551 DOI: 10.1038/srep30259] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2015] [Accepted: 07/04/2016] [Indexed: 01/05/2023] Open
Abstract
Retinal bipolar cells (BCs) divide photoreceptor output into different channels for the parallel extraction of temporal and chromatic stimulus properties. In rodents, five types of OFF BCs have been differentiated, based on morphological and functional criteria, but their electrophysiological characterization remains incomplete. This study analyzed OFF BCs with the patch clamp technique in acute slices of rat retina. Their specific voltage-dependent currents and glutamate responses are shown to represent individual fingerprints which define the signal processing and filtering properties of each cell type and allow their unequivocal identification. Two additions to the rat BC repertoire are presented: OFF BC-2', a variation of BC-2 with wider axonal arbours and prominent Na(+) currents, is described for the first time in rodents, and OFF BC-3b, previously identified in mouse, is electrophysiologically characterized in rat. Moreover, the glutamate responses of rat OFF BCs are shown to be differentially sensitive to AMPA- and kainate-receptor blockers and to modulation by nitric oxide (NO) through a cGMP-dependent mechanism. These results contribute to our understanding of the diversity and function of bipolar cells in mammals.
Collapse
|
44
|
Qiao SN, Zhang Z, Ribelayga CP, Zhong YM, Zhang DQ. Multiple cone pathways are involved in photic regulation of retinal dopamine. Sci Rep 2016; 6:28916. [PMID: 27356880 PMCID: PMC4928117 DOI: 10.1038/srep28916] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2016] [Accepted: 06/10/2016] [Indexed: 12/24/2022] Open
Abstract
Dopamine is a key neurotransmitter in the retina and plays a central role in the light adaptive processes of the visual system. The sole source of retinal dopamine is dopaminergic amacrine cells (DACs). We and others have previously demonstrated that DACs are activated by rods, cones, and intrinsically photosensitive retinal ganglion cells (ipRGCs) upon illumination. However, it is still not clear how each class of photosensitive cells generates light responses in DACs. We genetically isolated cone function in mice to specifically examine the cone-mediated responses of DACs and their neural pathways. In addition to the reported excitatory input to DACs from light-increment (ON) bipolar cells, we found that cones alternatively signal to DACs via a retrograde signalling pathway from ipRGCs. Cones also produce ON and light-decrement (OFF) inhibitory responses in DACs, which are mediated by other amacrine cells, likely driven by type 1 and type 2/3a OFF bipolar cells, respectively. Dye injections indicated that DACs had similar morphological profiles with or without ON/OFF inhibition. Our data demonstrate that cones utilize specific parallel excitatory and inhibitory circuits to modulate DAC activity and efficiently regulate dopamine release and the light-adaptive state of the retina.
Collapse
Affiliation(s)
- Sheng-Nan Qiao
- Institutes of Brain Science, Fudan University, Shanghai 200032, China
- Eye Research Institute, Oakland University, Rochester, MI 48309, USA
| | - Zhijing Zhang
- Ruiz Department of Ophthalmology and Visual Science, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, TX 77030, USA
| | - Christophe P. Ribelayga
- Ruiz Department of Ophthalmology and Visual Science, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, TX 77030, USA
- Graduate School of Biomedical Sciences, The University of Texas Health Science Center at Houston, Houston, TX 77030, USA
| | - Yong-Mei Zhong
- Institutes of Brain Science, Fudan University, Shanghai 200032, China
- State Key Laboratory of Medical Neurobiology, Fudan University, Shanghai 200032, China
- Collaborative Innovation Center for Brain Science, Fudan University, Shanghai 200032, China
| | - Dao-Qi Zhang
- Eye Research Institute, Oakland University, Rochester, MI 48309, USA
| |
Collapse
|
45
|
Rosa JM, Ruehle S, Ding H, Lagnado L. Crossover Inhibition Generates Sustained Visual Responses in the Inner Retina. Neuron 2016; 90:308-19. [PMID: 27068790 PMCID: PMC4848346 DOI: 10.1016/j.neuron.2016.03.015] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2015] [Revised: 01/21/2016] [Accepted: 03/02/2016] [Indexed: 12/23/2022]
Abstract
In daylight, the input to the retinal circuit is provided primarily by cone photoreceptors acting as band-pass filters, but the retinal output also contains neuronal populations transmitting sustained signals. Using in vivo imaging of genetically encoded calcium reporters, we investigated the circuits that generate these sustained channels within the inner retina of zebrafish. In OFF bipolar cells, sustained transmission was found to depend on crossover inhibition from the ON pathway through GABAergic amacrine cells. In ON bipolar cells, the amplitude of low-frequency signals was regulated by glycinergic amacrine cells, while GABAergic inhibition regulated the gain of band-pass signals. We also provide the first functional description of a subset of sustained ON bipolar cells in which synaptic activity was suppressed by fluctuations at frequencies above ∼0.2 Hz. These results map out the basic circuitry by which the inner retina generates sustained visual signals and describes a new function of crossover inhibition.
Collapse
Affiliation(s)
- Juliana M Rosa
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge, CB2 0QH, UK
| | - Sabine Ruehle
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge, CB2 0QH, UK
| | - Huayu Ding
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge, CB2 0QH, UK
| | - Leon Lagnado
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge, CB2 0QH, UK; School of Life Sciences, University of Sussex, Brighton, BN1 9QG, UK.
| |
Collapse
|
46
|
|
47
|
Gayet-Primo J, Puthussery T. Alterations in Kainate Receptor and TRPM1 Localization in Bipolar Cells after Retinal Photoreceptor Degeneration. Front Cell Neurosci 2015; 9:486. [PMID: 26733812 PMCID: PMC4686838 DOI: 10.3389/fncel.2015.00486] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2015] [Accepted: 11/30/2015] [Indexed: 11/21/2022] Open
Abstract
Photoreceptor degeneration differentially impacts glutamatergic signaling in downstream On and Off bipolar cells. In rodent models, photoreceptor degeneration leads to loss of glutamatergic signaling in On bipolar cells, whereas Off bipolar cells appear to retain glutamate sensitivity, even after extensive photoreceptor loss. The localization and identity of the receptors that mediate these residual glutamate responses in Off bipolar cells have not been determined. Recent studies show that macaque and mouse Off bipolar cells receive glutamatergic input primarily through kainate-type glutamate receptors. Here, we studied the impact of photoreceptor degeneration on glutamate receptor and their associated proteins in Off and On bipolar cells. We show that the kainate receptor subunit, GluK1, persists in remodeled Off bipolar cell dendrites of the rd10 mouse retina. However, the pattern of expression is altered and the intensity of staining is reduced compared to wild-type retina. The kainate receptor auxiliary subunit, Neto1, also remains in Off bipolar cell dendrites after extensive photoreceptor degeneration. Similar preservation of kainate receptor subunits was evident in human retina in which photoreceptors had degenerated due to serous retinal detachment. In contrast, photoreceptor degeneration leads to loss of synaptic expression of TRPM1 in mouse and human On bipolar cells, but strong somatic expression remains. These findings demonstrate that Off bipolar cells retain dendritic glutamate receptors during retinal degeneration and could thus serve as a conduit for signal transmission from transplanted or optogenetically restored photoreceptors.
Collapse
Affiliation(s)
- Jacqueline Gayet-Primo
- Casey Eye Institute, Department of Ophthalmology, Oregon Health and Science University, Portland OR, USA
| | - Theresa Puthussery
- Casey Eye Institute, Department of Ophthalmology, Oregon Health and Science University, Portland OR, USA
| |
Collapse
|
48
|
Ichinose T, Hellmer CB. Differential signalling and glutamate receptor compositions in the OFF bipolar cell types in the mouse retina. J Physiol 2015; 594:883-94. [PMID: 26553530 DOI: 10.1113/jp271458] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2015] [Accepted: 11/04/2015] [Indexed: 12/22/2022] Open
Abstract
KEY POINTS Using whole-cell clamp methods, we characterized the temporal coding in each type of OFF bipolar cell. We found that type 2 and 3a cells are transient, type 1 and 4 cells are sustained, and type 3b cells are intermediate. The light-evoked excitatory postsynaptic potentials in some types were rectified, suggesting that they provide inputs to the non-linear ganglion cells. Visual signalling from the photoreceptors was mediated exclusively through the kainate receptors in the transient OFF bipolar cells, whereas both kainate and AMPA receptors contributed in the other cells. This study demonstrates, for the first time, that parallel visual encoding starts at the OFF bipolar cells in a type-specific manner. ABSTRACT The retina is the entrance to the visual system, which receives various kinds of image signals and forms multiple encoding pathways. The second-order retinal neurons, the bipolar cells, are thought to initiate multiple neural streams by encoding various visual signals in different types of cells. However, the functions of each bipolar cell type have not been fully understood. We investigated whether OFF bipolar cells encode visual signals in a type-dependent manner. We recorded the changes in the bipolar cell voltage in response to two input functions: step and sinusoidal light stimuli. Type 1 and 4 OFF bipolar cells were sustained cells and responded to sinusoidal stimuli over a broad range of frequencies. Type 2 and 3a cells were transient and exhibited band-pass filtering. Type 3b cells were in the middle of these two groups. The distinct temporal responses might be attributed to different types of glutamate receptors. We examined the AMPA and kainate glutamate receptor composition in each bipolar cell type. The light responses in the transient OFF bipolar cells were exclusively mediated by kainate receptors. Although the kainate receptors mediated the light responses in the sustained cells, the AMPA receptors also mediated a portion of the responses in sustained cells. Furthermore, we found that some types of cells were rectified more than other types. Taken together, we found that the OFF bipolar cells encode diverse temporal image signals in a type-dependent manner, confirming that each type of OFF bipolar cell initiates diverse temporal visual processing in parallel.
Collapse
Affiliation(s)
- Tomomi Ichinose
- Department of Anatomy and Cell Biology, Wayne State University School of Medicine, Detroit, MI 48201, USA.,Department of Ophthalmology, Wayne State University School of Medicine, Detroit, MI 48201, USA
| | - Chase B Hellmer
- Department of Anatomy and Cell Biology, Wayne State University School of Medicine, Detroit, MI 48201, USA
| |
Collapse
|
49
|
Abstract
The mammalian retina is an important model system for studying neural circuitry: Its role in sensation is clear, its cell types are relatively well defined, and its responses to natural stimuli-light patterns-can be studied in vitro. To solve the retina, we need to understand how the circuits presynaptic to its output neurons, ganglion cells, divide the visual scene into parallel representations to be assembled and interpreted by the brain. This requires identifying the component interneurons and understanding how their intrinsic properties and synapses generate circuit behaviors. Because the cellular composition and fundamental properties of the retina are shared across species, basic mechanisms studied in the genetically modifiable mouse retina apply to primate vision. We propose that the apparent complexity of retinal computation derives from a straightforward mechanism-a dynamic balance of synaptic excitation and inhibition regulated by use-dependent synaptic depression-applied differentially to the parallel pathways that feed ganglion cells.
Collapse
Affiliation(s)
- Jonathan B Demb
- Department of Ophthalmology and Visual Science and Department of Cellular and Molecular Physiology, Yale University, New Haven, Connecticut 06511;
| | - Joshua H Singer
- Department of Biology, University of Maryland, College Park, Maryland 20742;
| |
Collapse
|
50
|
Thoreson WB. Horizontal slices of mouse retina expose horizontal cells and their properties (Commentary on Feigenspan & Babai). Eur J Neurosci 2015; 42:2613-4. [PMID: 26296395 PMCID: PMC4626275 DOI: 10.1111/ejn.13050] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Affiliation(s)
- Wallace B Thoreson
- Truhlsen Eye Institute and Departments of Ophthalmology & Visual Sciences and Pharmacology & Experimental Neuroscience, University of Nebraska Medical Center, 4050 Durham Research Center 1, Omaha, NE, 68198-5840, USA
| |
Collapse
|