1
|
Hellevik AM, Mardoum P, Hahn J, Kölsch Y, D'Orazi FD, Suzuki SC, Godinho L, Lawrence O, Rieke F, Shekhar K, Sanes JR, Baier H, Baden T, Wong RO, Yoshimatsu T. Ancient origin of the rod bipolar cell pathway in the vertebrate retina. Nat Ecol Evol 2024; 8:1165-1179. [PMID: 38627529 DOI: 10.1038/s41559-024-02404-w] [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] [Received: 10/04/2023] [Accepted: 03/20/2024] [Indexed: 04/30/2024]
Abstract
Vertebrates rely on rod photoreceptors for vision in low-light conditions. The specialized downstream circuit for rod signalling, called the primary rod pathway, is well characterized in mammals, but circuitry for rod signalling in non-mammals is largely unknown. Here we demonstrate that the mammalian primary rod pathway is conserved in zebrafish, which diverged from extant mammals ~400 million years ago. Using single-cell RNA sequencing, we identified two bipolar cell types in zebrafish that are related to mammalian rod bipolar cell (RBCs), the only bipolar type that directly carries rod signals from the outer to the inner retina in the primary rod pathway. By combining electrophysiology, histology and ultrastructural reconstruction of the zebrafish RBCs, we found that, similar to mammalian RBCs, both zebrafish RBC types connect with all rods in their dendritic territory and provide output largely onto amacrine cells. The wiring pattern of the amacrine cells postsynaptic to one RBC type is strikingly similar to that of mammalian RBCs and their amacrine partners, suggesting that the cell types and circuit design of the primary rod pathway emerged before the divergence of teleost fish and mammals. The second RBC type, which forms separate pathways, was either lost in mammals or emerged in fish.
Collapse
Affiliation(s)
- Ayana M Hellevik
- Department of Biological Structure, University of Washington, Seattle, WA, USA
| | - Philip Mardoum
- Department of Biological Structure, University of Washington, Seattle, WA, USA
| | - Joshua Hahn
- Department of Chemical and Biomolecular Engineering; Helen Wills Neuroscience Institute; Vision Sciences Graduate Program; California Institute of Quantitative Biosciences (QB3), University of California Berkley, Berkeley, CA, USA
| | - Yvonne Kölsch
- Department Genes - Circuits - Behavior, Max Planck Institute for Biological Intelligence, Martinsried, Germany
| | - Florence D D'Orazi
- Department of Biological Structure, University of Washington, Seattle, WA, USA
| | - Sachihiro C Suzuki
- Department of Biological Structure, University of Washington, Seattle, WA, USA
| | - Leanne Godinho
- Institute of Neuronal Cell Biology, Technische Universität München, Munich, Germany
| | - Owen Lawrence
- Department of Biological Structure, University of Washington, Seattle, WA, USA
| | - Fred Rieke
- Department of Physiology and Biophysics, University of Washington, Seattle, WA, USA
- Vision Science Center, University of Washington, Seattle, WA, USA
| | - Karthik Shekhar
- Department of Chemical and Biomolecular Engineering; Helen Wills Neuroscience Institute; Vision Sciences Graduate Program; California Institute of Quantitative Biosciences (QB3), University of California Berkley, Berkeley, CA, USA
- Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Joshua R Sanes
- Department of Molecular and Cellular Biology, and Center for Brain Science, Harvard University, Cambridge, MA, USA
| | - Herwig Baier
- Department Genes - Circuits - Behavior, Max Planck Institute for Biological Intelligence, Martinsried, Germany
| | - Tom Baden
- School of Life Sciences, University of Sussex, Brighton, UK
- Institute of Ophthalmic Research, University of Tübingen, Tübingen, Germany
| | - Rachel O Wong
- Department of Biological Structure, University of Washington, Seattle, WA, USA
| | - Takeshi Yoshimatsu
- Department of Ophthalmology and Visual Sciences, Washington University in St Louis School of Medicine, St Louis, MO, USA.
- BioRTC, Yobe State University, Damatsuru, Yobe, Nigeria.
| |
Collapse
|
2
|
Kilpeläinen M, Westö J, Tiihonen J, Laihi A, Takeshita D, Rieke F, Ala-Laurila P. Primate retina trades single-photon detection for high-fidelity contrast encoding. Nat Commun 2024; 15:4501. [PMID: 38802354 PMCID: PMC11130139 DOI: 10.1038/s41467-024-48750-y] [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: 02/01/2023] [Accepted: 05/10/2024] [Indexed: 05/29/2024] Open
Abstract
How the spike output of the retina enables human visual perception is not fully understood. Here, we address this at the sensitivity limit of vision by correlating human visual perception with the spike outputs of primate ON and OFF parasol (magnocellular) retinal ganglion cells in tightly matching stimulus conditions. We show that human vision at its ultimate sensitivity limit depends on the spike output of the ON but not the OFF retinal pathway. Consequently, nonlinear signal processing in the retinal ON pathway precludes perceptual detection of single photons in darkness but enables quantal-resolution discrimination of differences in light intensity.
Collapse
Affiliation(s)
- Markku Kilpeläinen
- Department of Psychology and Logopedics, University of Helsinki, Helsinki, Finland
- Molecular and Integrative Biosciences Research Programme, University of Helsinki, Helsinki, Finland
| | - Johan Westö
- Department of Neuroscience and Biomedical Engineering, Aalto University, Espoo, Finland
| | - Jussi Tiihonen
- Molecular and Integrative Biosciences Research Programme, University of Helsinki, Helsinki, Finland
- Department of Neuroscience and Biomedical Engineering, Aalto University, Espoo, Finland
| | - Anton Laihi
- Molecular and Integrative Biosciences Research Programme, University of Helsinki, Helsinki, Finland
| | - Daisuke Takeshita
- Molecular and Integrative Biosciences Research Programme, University of Helsinki, Helsinki, Finland
| | - Fred Rieke
- Department of Physiology and Biophysics, University of Washington, Seattle, WA, US
| | - Petri Ala-Laurila
- Molecular and Integrative Biosciences Research Programme, University of Helsinki, Helsinki, Finland.
- Department of Neuroscience and Biomedical Engineering, Aalto University, Espoo, Finland.
| |
Collapse
|
3
|
Morshedian A, Jiang Z, Radu RA, Fain GL, Sampath AP. Genetic manipulation of rod-cone differences in mouse retina. PLoS One 2024; 19:e0300584. [PMID: 38709779 PMCID: PMC11073714 DOI: 10.1371/journal.pone.0300584] [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] [Received: 12/28/2023] [Accepted: 03/01/2024] [Indexed: 05/08/2024] Open
Abstract
Though rod and cone photoreceptors use similar phototransduction mechanisms, previous model calculations have indicated that the most important differences in their light responses are likely to be differences in amplification of the G-protein cascade, different decay rates of phosphodiesterase (PDE) and pigment phosphorylation, and different rates of turnover of cGMP in darkness. To test this hypothesis, we constructed TrUx;GapOx rods by crossing mice with decreased transduction gain from decreased transducin expression, with mice displaying an increased rate of PDE decay from increased expression of GTPase-activating proteins (GAPs). These two manipulations brought the sensitivity of TrUx;GapOx rods to within a factor of 2 of WT cone sensitivity, after correcting for outer-segment dimensions. These alterations did not, however, change photoreceptor adaptation: rods continued to show increment saturation though at a higher background intensity. These experiments confirm model calculations that rod responses can mimic some (though not all) of the features of cone responses after only a few changes in the properties of transduction proteins.
Collapse
Affiliation(s)
- Ala Morshedian
- Department of Ophthalmology and Stein Eye Institute, David Geffen School of Medicine, University of California, Los Angeles, California, United States of America
| | - Zhichun Jiang
- Department of Ophthalmology and Stein Eye Institute, David Geffen School of Medicine, University of California, Los Angeles, California, United States of America
| | - Roxana A. Radu
- Department of Ophthalmology and Stein Eye Institute, David Geffen School of Medicine, University of California, Los Angeles, California, United States of America
| | - Gordon L. Fain
- Department of Ophthalmology and Stein Eye Institute, David Geffen School of Medicine, University of California, Los Angeles, California, United States of America
| | - Alapakkam P. Sampath
- Department of Ophthalmology and Stein Eye Institute, David Geffen School of Medicine, University of California, Los Angeles, California, United States of America
| |
Collapse
|
4
|
Kojima K, Yanagawa M, Imamoto Y, Yamano Y, Wada A, Shichida Y, Yamashita T. Convergent mechanism underlying the acquisition of vertebrate scotopic vision. J Biol Chem 2024; 300:107175. [PMID: 38499150 PMCID: PMC11007431 DOI: 10.1016/j.jbc.2024.107175] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2024] [Revised: 03/10/2024] [Accepted: 03/13/2024] [Indexed: 03/20/2024] Open
Abstract
High sensitivity of scotopic vision (vision in dim light conditions) is achieved by the rods' low background noise, which is attributed to a much lower thermal activation rate (kth) of rhodopsin compared with cone pigments. Frogs and nocturnal geckos uniquely possess atypical rods containing noncanonical cone pigments that exhibit low kth, mimicking rhodopsin. Here, we investigated the convergent mechanism underlying the low kth of rhodopsins and noncanonical cone pigments. Our biochemical analysis revealed that the kth of canonical cone pigments depends on their absorption maximum (λmax). However, rhodopsin and noncanonical cone pigments showed a substantially lower kth than predicted from the λmax dependency. Given that the λmax is inversely proportional to the activation energy of the pigments in the Hinshelwood distribution-based model, our findings suggest that rhodopsin and noncanonical cone pigments have convergently acquired low frequency of spontaneous-activation attempts, including thermal fluctuations of the protein moiety, in the molecular evolutionary processes from canonical cone pigments, which contributes to highly sensitive scotopic vision.
Collapse
Affiliation(s)
- Keiichi Kojima
- Department of Biophysics, Graduate School of Science, Kyoto University, Kyoto, Japan; Faculty of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, Japan
| | - Masataka Yanagawa
- Cellular Informatics Laboratory, RIKEN Cluster for Pioneering Research, Wako, Japan; Molecular and Cellular Biochemistry, Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, Miyagi, Japan
| | - Yasushi Imamoto
- Department of Biophysics, Graduate School of Science, Kyoto University, Kyoto, Japan
| | - Yumiko Yamano
- Comprehensive Education and Research Center, Kobe Pharmaceutical University, Kobe, Japan
| | - Akimori Wada
- Laboratory of Organic Chemistry for Life Science, Kobe Pharmaceutical University, Kobe, Japan
| | - Yoshinori Shichida
- Department of Biophysics, Graduate School of Science, Kyoto University, Kyoto, Japan; Research Organization for Science and Technology, Ritsumeikan University, Kusatsu, Shiga, Japan
| | - Takahiro Yamashita
- Department of Biophysics, Graduate School of Science, Kyoto University, Kyoto, Japan.
| |
Collapse
|
5
|
Bocchero U, Pahlberg J. Origin of Discrete and Continuous Dark Noise in Rod Photoreceptors. eNeuro 2023; 10:ENEURO.0390-23.2023. [PMID: 37973380 PMCID: PMC10687842 DOI: 10.1523/eneuro.0390-23.2023] [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: 10/06/2023] [Accepted: 11/02/2023] [Indexed: 11/19/2023] Open
Abstract
The detection of a single photon by a rod photoreceptor is limited by two sources of physiological noise, called discrete and continuous noise. Discrete noise occurs as intermittent current deflections with a waveform very similar to that of the single-photon response to real light and is thought to be produced by spontaneous activation of rhodopsin. Continuous noise occurs as random and continuous fluctuations in outer-segment current and is usually attributed to some intermediate in the phototransduction cascade. To confirm the origin of these noise sources, we have recorded from retinas of mouse lines with rods having reduced levels of rhodopsin, transducin, or phosphodiesterase. We show that the rate of discrete noise is diminished in proportion to the decrease in rhodopsin concentration, and that continuous noise is independent of transducin concentration but clearly elevated when the level of phosphodiesterase is reduced. Our experiments provide new molecular evidence that discrete noise is indeed produced by rhodopsin itself, and that continuous noise is generated by spontaneous activation of phosphodiesterase resulting in random fluctuations in outer-segment current.
Collapse
Affiliation(s)
- Ulisse Bocchero
- Photoreceptor Physiology Group, National Eye Institute, National Institutes of Health, Bethesda, Maryland 20892-2510
| | - Johan Pahlberg
- Photoreceptor Physiology Group, National Eye Institute, National Institutes of Health, Bethesda, Maryland 20892-2510
| |
Collapse
|
6
|
Hellevik AM, Mardoum P, Hahn J, Kölsch Y, D’Orazi FD, Suzuki SC, Godinho L, Lawrence O, Rieke F, Shekhar K, Sanes JR, Baier H, Baden T, Wong RO, Yoshimatsu T. Ancient origin of the rod bipolar cell pathway in the vertebrate retina. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.09.12.557433. [PMID: 37771914 PMCID: PMC10525478 DOI: 10.1101/2023.09.12.557433] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/30/2023]
Abstract
Vertebrates rely on rod photoreceptors for vision in low-light conditions1. Mammals have a specialized downstream circuit for rod signaling called the primary rod pathway, which comprises specific cell types and wiring patterns that are thought to be unique to this lineage2-6. Thus, it has been long assumed that the primary rod pathway evolved in mammals3,5-7. Here, we challenge this view by demonstrating that the mammalian primary rod pathway is conserved in zebrafish, which diverged from extant mammals ~400 million years ago. Using single-cell RNA-sequencing, we identified two bipolar cell (BC) types in zebrafish that are related to mammalian rod BCs (RBCs) of the primary rod pathway. By combining electrophysiology, histology, and ultrastructural reconstruction of the zebrafish RBCs, we found that, like mammalian RBCs8, both zebrafish RBC types connect with all rods and red-cones in their dendritic territory, and provide output largely onto amacrine cells. The wiring pattern of the amacrine cells post-synaptic to one RBC type is strikingly similar to that of mammalian RBCs. This suggests that the cell types and circuit design of the primary rod pathway may have emerged before the divergence of teleost fish and amniotes (mammals, bird, reptiles). The second RBC type in zebrafish, which forms separate pathways from the first RBC type, is either lost in mammals or emerged in fish to serve yet unknown roles.
Collapse
Affiliation(s)
- Ayana M Hellevik
- Department of Biological Structure, University of Washington, Seattle, WA 98195, USA
| | - Philip Mardoum
- Department of Biological Structure, University of Washington, Seattle, WA 98195, USA
| | - Joshua Hahn
- Department of Chemical and Biomolecular Engineering; Helen Wills Neuroscience Institute; Vision Sciences Graduate Program; California Institute of Quantitative Biosciences (QB3), University of California Berkley, Berkeley, CA 94720, USA
| | - Yvonne Kölsch
- Department of Molecular & Cellular Biology and Center for Brain Science, Harvard University, Cambridge, MA 02138, USA
- Max Planck Institute for Biological Intelligence, Department Genes – Circuits – Behavior, 82152 Martinsried, Germany
| | - Florence D D’Orazi
- Department of Biological Structure, University of Washington, Seattle, WA 98195, USA
| | - Sachihiro C. Suzuki
- Department of Biological Structure, University of Washington, Seattle, WA 98195, USA
| | - Leanne Godinho
- Institute of Neuronal Cell Biology, Technische Universität München, 80802 Munich, Germany
| | - Owen Lawrence
- Department of Biological Structure, University of Washington, Seattle, WA 98195, USA
| | - Fred Rieke
- Department of Physiology and Biophysics, University of Washington, Seattle, WA 98195, USA
- Vision Science Center, University of Washington, Seattle, WA 98195, USA
| | - Karthik Shekhar
- Department of Chemical and Biomolecular Engineering; Helen Wills Neuroscience Institute; Vision Sciences Graduate Program; California Institute of Quantitative Biosciences (QB3), University of California Berkley, Berkeley, CA 94720, USA
- Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Joshua R Sanes
- Department of Molecular & Cellular Biology and Center for Brain Science, Harvard University, Cambridge, MA 02138, USA
| | - Herwig Baier
- Max Planck Institute for Biological Intelligence, Department Genes – Circuits – Behavior, 82152 Martinsried, Germany
| | - Tom Baden
- School of Life Sciences, University of Sussex, Brighton, BN1 9QG, UK
- Institute of Ophthalmic Research, University of Tübingen, Tübingen, 72076, Germany
| | - Rachel O Wong
- Department of Biological Structure, University of Washington, Seattle, WA 98195, USA
| | - Takeshi Yoshimatsu
- Department of Ophthalmology & Visual Sciences, Washington University in St Louis School of Medicine, St Louis, MO 63110, USA
- BioRTC, Yobe State University, Damatsuru, Yobe 620101, Nigeria
| |
Collapse
|
7
|
Dittrich A, Ramesh G, Jung M, Schmitz F. Rabconnectin-3α/DMXL2 Is Locally Enriched at the Synaptic Ribbon of Rod Photoreceptor Synapses. Cells 2023; 12:1665. [PMID: 37371135 DOI: 10.3390/cells12121665] [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: 04/28/2023] [Revised: 06/08/2023] [Accepted: 06/17/2023] [Indexed: 06/29/2023] Open
Abstract
Ribbon synapses reliably transmit synaptic signals over a broad signalling range. Rod photoreceptor ribbon synapses are capable of transmitting signals generated by the absorption of single photons. The high precision of ribbon synapses emphasizes the need for particularly efficient signalling mechanisms. Synaptic ribbons are presynaptic specializations of ribbon synapses and are anchored to the active zone. Synaptic ribbons bind many synaptic vesicles that are delivered to the active zone for continuous and faithful signalling. In the present study we demonstrate with independent antibodies at the light- and electron microscopic level that rabconnectin-3α (RC3α)-alternative name Dmx-like 2 (DMXL2)-is localized to the synaptic ribbons of rod photoreceptor synapses in the mouse retina. In the brain, RC3α-containing complexes are known to interact with important components of synaptic vesicles, including Rab3-activating/inactivating enzymes, priming proteins and the vesicular H+-ATPase that acidifies the synaptic vesicle lumen to promote full neurotransmitter loading. The association of RC3α/DMXL2 with rod synaptic ribbons of the mouse retina could enable these structures to deliver only fully signalling-competent synaptic vesicles to the active zone thus contributing to reliable synaptic communication.
Collapse
Affiliation(s)
- Alina Dittrich
- Institute of Anatomy and Cell Biology, Saarland University, 66421 Homburg, Germany
| | - Girish Ramesh
- Institute of Anatomy and Cell Biology, Saarland University, 66421 Homburg, Germany
- Institute of Biophysics, Saarland University, 66421 Homburg, Germany
| | - Martin Jung
- Institute of Medical Biochemistry and Molecular Biology, Saarland University, 66421 Homburg, Germany
| | - Frank Schmitz
- Institute of Anatomy and Cell Biology, Saarland University, 66421 Homburg, Germany
| |
Collapse
|
8
|
Rodgers J, Hughes S, Lindner M, Allen AE, Ebrahimi AS, Storchi R, Peirson SN, Lucas RJ, Hankins MW. Functional integrity of visual coding following advanced photoreceptor degeneration. Curr Biol 2023; 33:474-486.e5. [PMID: 36630957 DOI: 10.1016/j.cub.2022.12.026] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2022] [Revised: 11/01/2022] [Accepted: 12/09/2022] [Indexed: 01/11/2023]
Abstract
Photoreceptor degeneration sufficient to produce severe visual loss often spares the inner retina. This raises hope for vision restoration treatments using optogenetics or electrical stimulation, which generate a replacement light input signal in surviving neurons. The success of these approaches is dependent on the capacity of surviving circuits of the visual system to generate and propagate an appropriate visual code in the face of neuroanatomical remodeling. To determine whether retinally degenerate animals possess this capacity, we generated a transgenic mouse model expressing the optogenetic actuator ReaChR in ON bipolar cells (second-order neurons in the visual projection). After crossing this with the rd1 model of photoreceptor degeneration, we compared ReaChR-derived responses with photoreceptor-driven responses in wild-type (WT) mice at the level of retinal ganglion cells and the visual thalamus. The ReaChR-driven responses in rd1 animals showed low photosensitivity, but in other respects generated a visual code that was very similar to the WT. ReaChR rd1 responses had high trial-to-trial reproducibility and showed sensitivity normalization to code contrast across background intensities. At the single unit level, ReaChR-derived responses exhibited broadly similar variations in response polarity, contrast sensitivity, and temporal frequency tuning as the WT. Units from the WT and ReaChR rd1 mice clustered together when subjected to unsupervised community detection based on stimulus-response properties. Our data reveal an impressive ability for surviving circuitry to recreate a rich visual code following advanced retinal degeneration and are promising for regenerative medicine in the central nervous system.
Collapse
Affiliation(s)
- Jessica Rodgers
- Faculty of Biology, Medicine & Health, University of Manchester, Upper Brook Street, Manchester M13 9PT, UK
| | - Steven Hughes
- Nuffield Laboratory of Ophthalmology, Sleep and Circadian Neuroscience Institute, Nuffield Department of Clinical Neurosciences, University of Oxford, South Parks Road, Oxford OX1 3QU, UK; Kavli Institute for Nanoscience Discovery, University of Oxford, South Parks Road, Oxford OX1 3QU, UK
| | - Moritz Lindner
- Nuffield Laboratory of Ophthalmology, Sleep and Circadian Neuroscience Institute, Nuffield Department of Clinical Neurosciences, University of Oxford, South Parks Road, Oxford OX1 3QU, UK; Institute of Physiology and Pathophysiology, Department of Neurophysiology, Philipps University, Deutschhausstr. 1-2, Marburg 35037, Germany
| | - Annette E Allen
- Faculty of Biology, Medicine & Health, University of Manchester, Upper Brook Street, Manchester M13 9PT, UK
| | - Aghileh S Ebrahimi
- Faculty of Biology, Medicine & Health, University of Manchester, Upper Brook Street, Manchester M13 9PT, UK
| | - Riccardo Storchi
- Faculty of Biology, Medicine & Health, University of Manchester, Upper Brook Street, Manchester M13 9PT, UK
| | - Stuart N Peirson
- Nuffield Laboratory of Ophthalmology, Sleep and Circadian Neuroscience Institute, Nuffield Department of Clinical Neurosciences, University of Oxford, South Parks Road, Oxford OX1 3QU, UK; Kavli Institute for Nanoscience Discovery, University of Oxford, South Parks Road, Oxford OX1 3QU, UK
| | - Robert J Lucas
- Faculty of Biology, Medicine & Health, University of Manchester, Upper Brook Street, Manchester M13 9PT, UK.
| | - Mark W Hankins
- Nuffield Laboratory of Ophthalmology, Sleep and Circadian Neuroscience Institute, Nuffield Department of Clinical Neurosciences, University of Oxford, South Parks Road, Oxford OX1 3QU, UK; Kavli Institute for Nanoscience Discovery, University of Oxford, South Parks Road, Oxford OX1 3QU, UK.
| |
Collapse
|
9
|
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
|
10
|
Fain GL. Vision: Life on the dark side. Curr Biol 2022; 32:R741-R743. [PMID: 35820384 DOI: 10.1016/j.cub.2022.06.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
Mice detect decreases in illumination in dim light near the visual threshold with OFF retinal ganglion cells.
Collapse
Affiliation(s)
- Gordon L Fain
- Departments of Integrative Biology/Physiology and Ophthalmology, Stein Eye Institute, University of California, Los Angeles, CA 90095, USA.
| |
Collapse
|
11
|
Westö J, Martyniuk N, Koskela S, Turunen T, Pentikäinen S, Ala-Laurila P. Retinal OFF ganglion cells allow detection of quantal shadows at starlight. Curr Biol 2022; 32:2848-2857.e6. [PMID: 35609606 DOI: 10.1016/j.cub.2022.04.092] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Revised: 04/01/2022] [Accepted: 04/28/2022] [Indexed: 02/01/2023]
Abstract
Perception of light in darkness requires no more than a handful of photons, and this remarkable behavioral performance can be directly linked to a particular retinal circuit-the retinal ON pathway. However, the neural limits of shadow detection in very dim light have remained unresolved. Here, we unravel the neural mechanisms that determine the sensitivity of mice (CBA/CaJ) to light decrements at the lowest light levels by measuring signals from the most sensitive ON and OFF retinal ganglion cell types and by correlating their signals with visually guided behavior. We show that mice can detect shadows when only a few photon absorptions are missing among thousands of rods. Behavioral detection of such "quantal" shadows relies on the retinal OFF pathway and is limited by noise and loss of single-photon signals in retinal processing. Thus, in the dim-light regime, light increments and decrements are encoded separately via the ON and OFF retinal pathways, respectively.
Collapse
Affiliation(s)
- Johan Westö
- Department of Neuroscience and Biomedical Engineering, Aalto University, 02150 Espoo, Finland
| | - Nataliia Martyniuk
- Department of Neuroscience and Biomedical Engineering, Aalto University, 02150 Espoo, Finland
| | - Sanna Koskela
- Faculty of Biological and Environmental Sciences, Molecular and Integrative Biosciences Research Programme, University of Helsinki, 00790 Helsinki, Finland
| | - Tuomas Turunen
- Department of Neuroscience and Biomedical Engineering, Aalto University, 02150 Espoo, Finland
| | - Santtu Pentikäinen
- Faculty of Biological and Environmental Sciences, Molecular and Integrative Biosciences Research Programme, University of Helsinki, 00790 Helsinki, Finland
| | - Petri Ala-Laurila
- Department of Neuroscience and Biomedical Engineering, Aalto University, 02150 Espoo, Finland; Faculty of Biological and Environmental Sciences, Molecular and Integrative Biosciences Research Programme, University of Helsinki, 00790 Helsinki, Finland.
| |
Collapse
|
12
|
Jin N, Tian LM, Fahrenfort I, Zhang Z, Postma F, Paul DL, Massey SC, Ribelayga CP. Genetic elimination of rod/cone coupling reveals the contribution of the secondary rod pathway to the retinal output. SCIENCE ADVANCES 2022; 8:eabm4491. [PMID: 35363529 PMCID: PMC10938630 DOI: 10.1126/sciadv.abm4491] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2021] [Accepted: 02/10/2022] [Indexed: 06/14/2023]
Abstract
In the retina, signals originating from rod and cone photoreceptors can reach retinal ganglion cells (RGCs)-the output neurons-through different pathways. However, little is known about the exact sensitivities and operating ranges of these pathways. Previously, we created rod- or cone-specific Cx36 knockout (KO) mouse lines. Both lines are deficient in rod/cone electrical coupling and therefore provide a way to selectively remove the secondary rod pathway. We measured the threshold of the primary rod pathway in RGCs of wild-type mice. Under pharmacological blockade of the primary rod pathway, the threshold was elevated. This secondary component was removed in the Cx36 KOs to unmask the threshold of the third rod pathway, still below cone threshold. In turn, the cone threshold was estimated by several independent methods. Our work defines the functionality of the secondary rod pathway and describes an additive contribution of the different pathways to the retinal output.
Collapse
Affiliation(s)
- Nange Jin
- Ruiz Department of Ophthalmology and Visual Science, McGovern Medical School, The University of Texas Health Science Center at Houston (UTHealth Houston), Houston, TX, USA
| | - Lian-Ming Tian
- Ruiz Department of Ophthalmology and Visual Science, McGovern Medical School, The University of Texas Health Science Center at Houston (UTHealth Houston), Houston, TX, USA
| | - Iris Fahrenfort
- Ruiz Department of Ophthalmology and Visual Science, McGovern Medical School, The University of Texas Health Science Center at Houston (UTHealth Houston), Houston, TX, USA
| | - Zhijing Zhang
- Ruiz Department of Ophthalmology and Visual Science, McGovern Medical School, The University of Texas Health Science Center at Houston (UTHealth Houston), Houston, TX, USA
| | - Friso Postma
- Department of Neurobiology, Medical School, Harvard University, Boston, MA, USA
| | - David L. Paul
- Department of Neurobiology, Medical School, Harvard University, Boston, MA, USA
| | - Stephen C. Massey
- Ruiz Department of Ophthalmology and Visual Science, McGovern Medical School, The University of Texas Health Science Center at Houston (UTHealth Houston), Houston, TX, USA
- Elizabeth Morford Distinguished Chair in Ophthalmology and Research Director, Ruiz Department of Ophthalmology and Visual Science, McGovern Medical School, The University of Texas Health Science Center at Houston (UTHealth Houston), Houston, TX, USA
| | - Christophe P. Ribelayga
- Ruiz Department of Ophthalmology and Visual Science, McGovern Medical School, The University of Texas Health Science Center at Houston (UTHealth Houston), Houston, TX, USA
- Bernice Weingarten Chair in Ophthalmology, Ruiz Department of Ophthalmology and Visual Science, McGovern Medical School, The University of Texas Health Science Center at Houston (UTHealth Houston), Houston, TX, USA
| |
Collapse
|
13
|
Brodrick EA, How MJ, Hemmi JM. Fiddler crab electroretinograms reveal vast circadian shifts in visual sensitivity and temporal summation in dim light. J Exp Biol 2022; 225:274663. [PMID: 35156128 PMCID: PMC8976941 DOI: 10.1242/jeb.243693] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Accepted: 02/04/2022] [Indexed: 11/20/2022]
Abstract
Many animals with compound eyes undergo major optical changes to adjust visual sensitivity from day to night, often under control of a circadian clock. In fiddler crabs, this presents most conspicuously in the huge volume increase of photopigment-packed rhabdoms and the widening of crystalline cone apertures at night. These changes are hypothesised to adjust the light flux to the photoreceptors and to alter optical sensitivity as the eye moves between light- and dark-adapted states. Here, we compare optical sensitivity in fiddler crab eyes (Gelasimus dampieri) during daytime and night via three electroretinogram (ERG) experiments performed on light- and dark-adapted crabs.
1) Light intensity required to elicit a threshold ERG response varied over six orders of magnitude, allowing more sensitive vision for discriminating small contrasts in dim light after dusk. During daytime, the eyes remained relatively insensitive, which would allow effective vision on bright mudflats, even after prolonged dark adaptation.
2) Flicker fusion frequency (FFF) experiments indicated that temporal summation is employed in dim light to increase light-gathering integration times and enhance visual sensitivity during both night and day.
3) ERG responses to flickering lights during 60 mins of dark adaptation increased at a faster rate and greater extent after sunset compared to daytime. However, even brief, dim and intermittent light exposure strongly disrupted dark-adaptation processes.
Together, these findings demonstrate effective light adaptation to optimise vision over the large range of light intensities that these animals experience.
Collapse
Affiliation(s)
| | - Martin J. How
- School of Biological Sciences, University of Bristol, Bristol, BS8 1TQ, UK
| | - Jan M. Hemmi
- School of Biological Sciences & UWA Oceans Institute, University of Western Australia, Perth, WA 6009, Australia
| |
Collapse
|
14
|
Real models: The limits of behavioural evidence for understanding the ANS. Behav Brain Sci 2021; 44:e186. [PMID: 34907874 DOI: 10.1017/s0140525x21001151] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Clarke and Beck use behavioural evidence to argue that (1) approximate ratio computations are sufficient for claiming that the approximate number system (ANS) represents the rationals, and (2) the ANS does not represent the reals. We argue that pure behaviour is a poor litmus test for this problem, and that we should trust the psychophysical models that place ANS representations within the reals.
Collapse
|
15
|
Kojima K, Matsutani Y, Yanagawa M, Imamoto Y, Yamano Y, Wada A, Shichida Y, Yamashita T. Evolutionary adaptation of visual pigments in geckos for their photic environment. SCIENCE ADVANCES 2021; 7:eabj1316. [PMID: 34597144 PMCID: PMC10938493 DOI: 10.1126/sciadv.abj1316] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/23/2021] [Accepted: 08/11/2021] [Indexed: 06/13/2023]
Abstract
Vertebrates generally have a single type of rod for scotopic vision and multiple types of cones for photopic vision. Noteworthily, nocturnal geckos transmuted ancestral photoreceptor cells into rods containing not rhodopsin but cone pigments, and, subsequently, diurnal geckos retransmuted these rods into cones containing cone pigments. High sensitivity of scotopic vision is underlain by the rod’s low background noise, which originated from a much lower spontaneous activation rate of rhodopsin than of cone pigments. Here, we revealed that nocturnal gecko cone pigments decreased their spontaneous activation rates to mimic rhodopsin, whereas diurnal gecko cone pigments recovered high rates similar to those of typical cone pigments. We also identified amino acid residues responsible for the alterations of the spontaneous activation rates. Therefore, we concluded that the switch between diurnality and nocturnality in geckos required not only morphological transmutation of photoreceptors but also adjustment of the spontaneous activation rates of visual pigments.
Collapse
Affiliation(s)
- Keiichi Kojima
- Department of Biophysics, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan
- Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama 700-8530, Japan
| | - Yuki Matsutani
- Department of Biophysics, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan
| | - Masataka Yanagawa
- Cellular Informatics Laboratory, RIKEN Cluster for Pioneering Research, 2-1 Hirosawa, Wako 351-0198, Japan
| | - Yasushi Imamoto
- Department of Biophysics, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan
| | - Yumiko Yamano
- Laboratory of Organic Chemistry for Life Science, Kobe Pharmaceutical University, Kobe 658-8558, Japan
| | - Akimori Wada
- Laboratory of Organic Chemistry for Life Science, Kobe Pharmaceutical University, Kobe 658-8558, Japan
| | - Yoshinori Shichida
- Department of Biophysics, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan
- Research Organization for Science and Technology, Ritsumeikan University, Kusatsu, Shiga 525-8577, Japan
| | - Takahiro Yamashita
- Department of Biophysics, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan
| |
Collapse
|
16
|
Abstract
Time is largely a hidden variable in vision. It is the condition for seeing interesting things such as spatial forms and patterns, colours and movements in the external world, and yet is not meant to be noticed in itself. Temporal aspects of visual processing have received comparatively little attention in research. Temporal properties have been made explicit mainly in measurements of resolution and integration in simple tasks such as detection of spatially homogeneous flicker or light pulses of varying duration. Only through a mechanistic understanding of their basis in retinal photoreceptors and circuits can such measures guide modelling of natural vision in different species and illuminate functional and evolutionary trade-offs. Temporal vision research would benefit from bridging traditions that speak different languages. Towards that goal, I here review studies from the fields of human psychophysics, retinal physiology and neuroethology, with a focus on fundamental constraints set by early vision. Summary: Simple measures of temporal vision such as the critical flicker frequency can be useful for modelling natural vision only if their relationship to photoreceptor responses and retinal processing is understood.
Collapse
Affiliation(s)
- Kristian Donner
- Molecular and Integrative Biosciences Research Programme, Faculty of Biological and Environmental Sciences, University of Helsinki, 00014 Helsinki, Finland
| |
Collapse
|
17
|
Whitaker CM, Nobles G, Ishibashi M, Massey SC. Rod and Cone Connections With Bipolar Cells in the Rabbit Retina. Front Cell Neurosci 2021; 15:662329. [PMID: 34025360 PMCID: PMC8134685 DOI: 10.3389/fncel.2021.662329] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Accepted: 04/12/2021] [Indexed: 11/13/2022] Open
Abstract
Rod and cone pathways are segregated in the first stage of the retina: cones synapse with both ON- and OFF-cone bipolar cells while rods contact only rod bipolar cells. However, there is an exception to this specific wiring in that rods also contact certain OFF cone bipolar cells, providing a tertiary rod pathway. Recently, it has been proposed that there is even more crossover between rod and cone pathways. Physiological recordings suggested that rod bipolar cells receive input from cones, and ON cone bipolar cells can receive input from rods, in addition to the established pathways. To image their rod and cone contacts, we have dye-filled individual rod bipolar cells in the rabbit retina. We report that approximately half the rod bipolar cells receive one or two cone contacts. Dye-filling AII amacrine cells, combined with subtractive labeling, revealed most of the ON cone bipolar cells to which they were coupled, including the occasional blue cone bipolar cell, identified by its contacts with blue cones. Imaging the AII-coupled ON cone bipolar dendrites in this way showed that they contact cones exclusively. We conclude that there is some limited cone input to rod bipolar cells, but we could find no evidence for rod contacts with ON cone bipolar cells. The tertiary rod OFF pathway operates via direct contacts between rods and OFF cone bipolar cells. In contrast, our results do not support the presence of a tertiary rod ON pathway in the rabbit retina.
Collapse
Affiliation(s)
| | | | | | - Stephen C. Massey
- Ruiz Department of Ophthalmology and Visual Science, McGovern Medical School, University of Texas Medical School at Houston, Houston, TX, United States
| |
Collapse
|
18
|
Nagy J, Ebbinghaus B, Hoon M, Sinha R. GABA A presynaptic inhibition regulates the gain and kinetics of retinal output neurons. eLife 2021; 10:60994. [PMID: 33904401 PMCID: PMC8110304 DOI: 10.7554/elife.60994] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2020] [Accepted: 04/06/2021] [Indexed: 12/16/2022] Open
Abstract
Output signals of neural circuits, including the retina, are shaped by a combination of excitatory and inhibitory signals. Inhibitory signals can act presynaptically on axon terminals to control neurotransmitter release and regulate circuit function. However, it has been difficult to study the role of presynaptic inhibition in most neural circuits due to lack of cell type-specific and receptor type-specific perturbations. In this study, we used a transgenic approach to selectively eliminate GABAA inhibitory receptors from select types of second-order neurons - bipolar cells - in mouse retina and examined how this affects the light response properties of the well-characterized ON alpha ganglion cell retinal circuit. Selective loss of GABAA receptor-mediated presynaptic inhibition causes an enhanced sensitivity and slower kinetics of light-evoked responses from ON alpha ganglion cells thus highlighting the role of presynaptic inhibition in gain control and temporal filtering of sensory signals in a key neural circuit in the mammalian retina.
Collapse
Affiliation(s)
- Jenna Nagy
- Department of Neuroscience, University of WisconsinMadisonUnited States
- McPherson Eye Research Institute, University of WisconsinMadisonUnited States
- Cellular and Molecular Pathology Training Program, University of WisconsinMadisonUnited States
| | - Briana Ebbinghaus
- McPherson Eye Research Institute, University of WisconsinMadisonUnited States
- Department of Ophthalmology and Visual Sciences, University of WisconsinMadisonUnited States
- Neuroscience Training Program, University of WisconsinMadisonUnited States
| | - Mrinalini Hoon
- Department of Neuroscience, University of WisconsinMadisonUnited States
- McPherson Eye Research Institute, University of WisconsinMadisonUnited States
- Department of Ophthalmology and Visual Sciences, University of WisconsinMadisonUnited States
| | - Raunak Sinha
- Department of Neuroscience, University of WisconsinMadisonUnited States
- McPherson Eye Research Institute, University of WisconsinMadisonUnited States
- Department of Ophthalmology and Visual Sciences, University of WisconsinMadisonUnited States
| |
Collapse
|
19
|
Threshold vision under full-field stimulation: Revisiting the minimum number of quanta necessary to evoke a visual sensation. Vision Res 2020; 180:1-10. [PMID: 33359896 DOI: 10.1016/j.visres.2020.11.010] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Revised: 11/21/2020] [Accepted: 11/28/2020] [Indexed: 12/12/2022]
Abstract
At the absolute threshold of vision, Hecht, Shlaer and Pirenne estimate that 5-14 photons are absorbed within a retinal area containing ~500 rods. Other estimates of scotopic threshold vision based on stimuli with different durations and focal areas range up to ~100,000 photons. Given that rod density varies with retinal eccentricity and the magnitude of the intrinsic noise increases with increasing stimulus area and duration, here we determine whether the scotopic threshold estimates with focal stimuli can be extended to full-field stimulation and whether summation explains inter-study differences. We show that full-field threshold vision (~1018 mm2, 10 ms duration) is more sensitive than at absolute threshold, requiring the absorption of ~1000 photons across ~91.96 million rods. A summation model is presented integrating our and published data and using a nominal exposure duration, criterion frequency of seeing, rod density, and retinal area that largely explains the inter-study differences and allows estimation of rods per photon ratio for any stimulus size and duration. The highest signal to noise ratio is defined by a peak rod convergence estimated at 53:4:1:2 (rods:rod bipolar cells:AII amacrine cells:retinal ganglion cells), in line with macaque anatomical estimates that show AII amacrine cells form the bottleneck in the rod pathway to set the scotopic visual limit. Our model estimations that the rods per photon ratio under full-field stimulation is ~3000X higher than at absolute threshold are in accordance with visual summation effects and provide an alternative approach for understanding the limits of scotopic vision.
Collapse
|
20
|
Yoshimatsu T, Schröder C, Nevala NE, Berens P, Baden T. Fovea-like Photoreceptor Specializations Underlie Single UV Cone Driven Prey-Capture Behavior in Zebrafish. Neuron 2020; 107:320-337.e6. [PMID: 32473094 PMCID: PMC7383236 DOI: 10.1016/j.neuron.2020.04.021] [Citation(s) in RCA: 68] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2019] [Revised: 02/13/2020] [Accepted: 04/21/2020] [Indexed: 01/04/2023]
Abstract
In the eye, the function of same-type photoreceptors must be regionally adjusted to process a highly asymmetrical natural visual world. Here, we show that UV cones in the larval zebrafish area temporalis are specifically tuned for UV-bright prey capture in their upper frontal visual field, which may use the signal from a single cone at a time. For this, UV-photon detection probability is regionally boosted more than 10-fold. Next, in vivo two-photon imaging, transcriptomics, and computational modeling reveal that these cones use an elevated baseline of synaptic calcium to facilitate the encoding of bright objects, which in turn results from expressional tuning of phototransduction genes. Moreover, the light-driven synaptic calcium signal is regionally slowed by interactions with horizontal cells and later accentuated at the level of glutamate release driving retinal networks. These regional differences tally with variations between peripheral and foveal cones in primates and hint at a common mechanistic origin.
Collapse
Affiliation(s)
| | - Cornelius Schröder
- Institute of Ophthalmic Research, University of Tübingen, Tübingen 72076, Germany; Center for Integrative Neuroscience, University of Tübingen, Tübingen 72076, Germany
| | - Noora E Nevala
- School of Life Sciences, University of Sussex, Brighton BN1 9QG, UK
| | - Philipp Berens
- Institute of Ophthalmic Research, University of Tübingen, Tübingen 72076, Germany; Center for Integrative Neuroscience, University of Tübingen, Tübingen 72076, Germany; Institute for Bioinformatics and Medical Informatics, University of Tübingen, Tübingen 72076, Germany
| | - Tom Baden
- School of Life Sciences, University of Sussex, Brighton BN1 9QG, UK; Institute of Ophthalmic Research, University of Tübingen, Tübingen 72076, Germany.
| |
Collapse
|
21
|
Jin N, Zhang Z, Keung J, Youn SB, Ishibashi M, Tian LM, Marshak DW, Solessio E, Umino Y, Fahrenfort I, Kiyama T, Mao CA, You Y, Wei H, Wu J, Postma F, Paul DL, Massey SC, Ribelayga CP. Molecular and functional architecture of the mouse photoreceptor network. SCIENCE ADVANCES 2020; 6:eaba7232. [PMID: 32832605 PMCID: PMC7439306 DOI: 10.1126/sciadv.aba7232] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/28/2019] [Accepted: 04/21/2020] [Indexed: 06/11/2023]
Abstract
Mouse photoreceptors are electrically coupled via gap junctions, but the relative importance of rod/rod, cone/cone, or rod/cone coupling is unknown. Furthermore, while connexin36 (Cx36) is expressed by cones, the identity of the rod connexin has been controversial. We report that FACS-sorted rods and cones both express Cx36 but no other connexins. We created rod- and cone-specific Cx36 knockout mice to dissect the photoreceptor network. In the wild type, Cx36 plaques at rod/cone contacts accounted for more than 95% of photoreceptor labeling and paired recordings showed the transjunctional conductance between rods and cones was ~300 pS. When Cx36 was eliminated on one side of the gap junction, in either conditional knockout, Cx36 labeling and rod/cone coupling were almost abolished. We could not detect direct rod/rod coupling, and cone/cone coupling was minor. Rod/cone coupling is so prevalent that indirect rod/cone/rod coupling via the network may account for previous reports of rod coupling.
Collapse
Affiliation(s)
- Nange Jin
- Ruiz Department of Ophthalmology and Visual Science, McGovern Medical School, UTHEALTH-The University of Texas Health Science Center at Houston, Houston, TX, USA
| | - Zhijing Zhang
- Ruiz Department of Ophthalmology and Visual Science, McGovern Medical School, UTHEALTH-The University of Texas Health Science Center at Houston, Houston, TX, USA
| | - Joyce Keung
- Ruiz Department of Ophthalmology and Visual Science, McGovern Medical School, UTHEALTH-The University of Texas Health Science Center at Houston, Houston, TX, USA
| | - Sean B. Youn
- Summer Research Program, McGovern Medical School, UTHEALTH-The University of Texas Health Science Center at Houston, Houston, TX, USA
- Undergraduate Program, William Marsh Rice University, Houston, TX, USA
| | - Munenori Ishibashi
- Ruiz Department of Ophthalmology and Visual Science, McGovern Medical School, UTHEALTH-The University of Texas Health Science Center at Houston, Houston, TX, USA
| | - Lian-Ming Tian
- Ruiz Department of Ophthalmology and Visual Science, McGovern Medical School, UTHEALTH-The University of Texas Health Science Center at Houston, Houston, TX, USA
| | - David W. Marshak
- Department of Neurobiology and Anatomy, McGovern Medical School, UTHEALTH-The University of Texas Health Science Center at Houston, Houston, TX, USA
- Neuroscience Research Center, UTHEALTH-The University of Texas Health Science Center at Houston, Houston, TX, USA
- Graduate School of Biomedical Sciences, MD Anderson Cancer Center/UTHEALTH-The University of Texas Health Science Center at Houston, Houston, TX, USA
- Program in Neuroscience, Graduate School of Biomedical Sciences, MD Anderson Cancer Center/UTHEALTH-The University of Texas Health Science Center at Houston, Houston, TX, USA
| | - Eduardo Solessio
- Center for Vision Research and SUNY Eye Institute, Department of Ophthalmology, SUNY Upstate Medical University, Syracuse, NY, USA
| | - Yumiko Umino
- Center for Vision Research and SUNY Eye Institute, Department of Ophthalmology, SUNY Upstate Medical University, Syracuse, NY, USA
| | - Iris Fahrenfort
- Ruiz Department of Ophthalmology and Visual Science, McGovern Medical School, UTHEALTH-The University of Texas Health Science Center at Houston, Houston, TX, USA
| | - Takae Kiyama
- Ruiz Department of Ophthalmology and Visual Science, McGovern Medical School, UTHEALTH-The University of Texas Health Science Center at Houston, Houston, TX, USA
| | - Chai-An Mao
- Ruiz Department of Ophthalmology and Visual Science, McGovern Medical School, UTHEALTH-The University of Texas Health Science Center at Houston, Houston, TX, USA
- Neuroscience Research Center, UTHEALTH-The University of Texas Health Science Center at Houston, Houston, TX, USA
- Graduate School of Biomedical Sciences, MD Anderson Cancer Center/UTHEALTH-The University of Texas Health Science Center at Houston, Houston, TX, USA
- Program in Neuroscience, Graduate School of Biomedical Sciences, MD Anderson Cancer Center/UTHEALTH-The University of Texas Health Science Center at Houston, Houston, TX, USA
| | - Yanan You
- The Vivian L. Smith Department of Neurosurgery, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, TX, USA
- Center for Stem Cell and Regenerative Medicine, The University of Texas Brown Foundation Institute of Molecular Medicine, Houston, TX, USA
| | - Haichao Wei
- The Vivian L. Smith Department of Neurosurgery, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, TX, USA
- Center for Stem Cell and Regenerative Medicine, The University of Texas Brown Foundation Institute of Molecular Medicine, Houston, TX, USA
| | - Jiaqian Wu
- Graduate School of Biomedical Sciences, MD Anderson Cancer Center/UTHEALTH-The University of Texas Health Science Center at Houston, Houston, TX, USA
- Program in Neuroscience, Graduate School of Biomedical Sciences, MD Anderson Cancer Center/UTHEALTH-The University of Texas Health Science Center at Houston, Houston, TX, USA
- The Vivian L. Smith Department of Neurosurgery, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, TX, USA
- Center for Stem Cell and Regenerative Medicine, The University of Texas Brown Foundation Institute of Molecular Medicine, Houston, TX, USA
| | - Friso Postma
- Department of Neurobiology, Medical School, Harvard University, Boston, MA, USA
| | - David L. Paul
- Department of Neurobiology, Medical School, Harvard University, Boston, MA, USA
| | - Stephen C. Massey
- Ruiz Department of Ophthalmology and Visual Science, McGovern Medical School, UTHEALTH-The University of Texas Health Science Center at Houston, Houston, TX, USA
- Summer Research Program, McGovern Medical School, UTHEALTH-The University of Texas Health Science Center at Houston, Houston, TX, USA
- Neuroscience Research Center, UTHEALTH-The University of Texas Health Science Center at Houston, Houston, TX, USA
- Graduate School of Biomedical Sciences, MD Anderson Cancer Center/UTHEALTH-The University of Texas Health Science Center at Houston, Houston, TX, USA
- Program in Neuroscience, Graduate School of Biomedical Sciences, MD Anderson Cancer Center/UTHEALTH-The University of Texas Health Science Center at Houston, Houston, TX, USA
- Elizabeth Morford Distinguished Chair in Ophthalmology and Research Director, Ruiz Department of Ophthalmology and Visual Science, McGovern Medical School, UTHEALTH-The University of Texas Health Science Center at Houston, Houston, TX, USA
| | - Christophe P. Ribelayga
- Ruiz Department of Ophthalmology and Visual Science, McGovern Medical School, UTHEALTH-The University of Texas Health Science Center at Houston, Houston, TX, USA
- Summer Research Program, McGovern Medical School, UTHEALTH-The University of Texas Health Science Center at Houston, Houston, TX, USA
- Neuroscience Research Center, UTHEALTH-The University of Texas Health Science Center at Houston, Houston, TX, USA
- Graduate School of Biomedical Sciences, MD Anderson Cancer Center/UTHEALTH-The University of Texas Health Science Center at Houston, Houston, TX, USA
- Program in Neuroscience, Graduate School of Biomedical Sciences, MD Anderson Cancer Center/UTHEALTH-The University of Texas Health Science Center at Houston, Houston, TX, USA
- Program in Biochemistry and Cellular Biology, Graduate School of Biomedical Sciences, MD Anderson Cancer Center/UTHEALTH-The University of Texas Health Science Center at Houston, Houston, TX, USA
- Bernice Weingarten Chair in Ophthalmology, Ruiz Department of Ophthalmology and Visual Science, McGovern Medical School, UTHEALTH-The University of Texas Health Science Center at Houston, Houston, TX, USA
| |
Collapse
|
22
|
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
|
23
|
Retinal Circuits for Seeing in the Dark. Neuron 2020; 104:435-437. [PMID: 31697918 DOI: 10.1016/j.neuron.2019.10.026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
How can we relate processing in the retina to an animal's behavior? In this issue of Neuron, Smeds et al. (2019) report that when "every photon counts," mice trade sensitivity for reliability to master visual tasks.
Collapse
|
24
|
Fahrenfort I, Ribelayga CP. Sensory Processing: Visual Sensitivity Gets High at Night. Curr Biol 2020; 30:R18-R20. [DOI: 10.1016/j.cub.2019.11.016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
|
25
|
Moser T, Grabner CP, Schmitz F. Sensory Processing at Ribbon Synapses in the Retina and the Cochlea. Physiol Rev 2020; 100:103-144. [DOI: 10.1152/physrev.00026.2018] [Citation(s) in RCA: 80] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
In recent years, sensory neuroscientists have made major efforts to dissect the structure and function of ribbon synapses which process sensory information in the eye and ear. This review aims to summarize our current understanding of two key aspects of ribbon synapses: 1) their mechanisms of exocytosis and endocytosis and 2) their molecular anatomy and physiology. Our comparison of ribbon synapses in the cochlea and the retina reveals convergent signaling mechanisms, as well as divergent strategies in different sensory systems.
Collapse
Affiliation(s)
- Tobias Moser
- Institute for Auditory Neuroscience and InnerEarLab, University Medical Center Göttingen, Göttingen, Germany; Auditory Neuroscience Group, Max Planck Institute for Experimental Medicine, Göttingen, Germany; Synaptic Nanophysiology Group, Max-Planck-Institute for Biophysical Chemistry, Göttingen, Germany; and Institute for Anatomy and Cell Biology, Department of Neuroanatomy, Medical School, Saarland University, Homburg, Germany
| | - Chad P. Grabner
- Institute for Auditory Neuroscience and InnerEarLab, University Medical Center Göttingen, Göttingen, Germany; Auditory Neuroscience Group, Max Planck Institute for Experimental Medicine, Göttingen, Germany; Synaptic Nanophysiology Group, Max-Planck-Institute for Biophysical Chemistry, Göttingen, Germany; and Institute for Anatomy and Cell Biology, Department of Neuroanatomy, Medical School, Saarland University, Homburg, Germany
| | - Frank Schmitz
- Institute for Auditory Neuroscience and InnerEarLab, University Medical Center Göttingen, Göttingen, Germany; Auditory Neuroscience Group, Max Planck Institute for Experimental Medicine, Göttingen, Germany; Synaptic Nanophysiology Group, Max-Planck-Institute for Biophysical Chemistry, Göttingen, Germany; and Institute for Anatomy and Cell Biology, Department of Neuroanatomy, Medical School, Saarland University, Homburg, Germany
| |
Collapse
|
26
|
Local, nonlinear effects of cGMP and Ca2+ reduce single photon response variability in retinal rods. PLoS One 2019; 14:e0225948. [PMID: 31805112 PMCID: PMC6894879 DOI: 10.1371/journal.pone.0225948] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2019] [Accepted: 11/14/2019] [Indexed: 11/26/2022] Open
Abstract
The single photon response (SPR) in vertebrate photoreceptors is inherently variable due to several stochastic events in the phototransduction cascade, the main one being the shutoff of photoactivated rhodopsin. Deactivation is driven by a random number of steps, each of random duration with final quenching occurring after a random delay. Nevertheless, variability of the SPR is relatively low, making the signal highly reliable. Several biophysical and mathematical mechanisms contributing to variability suppression have been examined by the authors. Here we investigate the contribution of local depletion of cGMP by PDE*, the non linear dependence of the photocurrent on cGMP, Ca2+ feedback by making use of a fully space resolved (FSR) mathematical model, applied to two species (mouse and salamander), by varying the cGMP diffusion rate severalfold and rod outer segment diameter by an order of magnitude, and by introducing new, more refined, and time dependent variability functionals. Globally well stirred (GWS) models, and to a lesser extent transversally well stirred models (TWS), underestimate the role of nonlinearities and local cGMP depletion in quenching the variability of the circulating current with respect to fully space resolved models (FSR). These distortions minimize the true extent to which SPR is stabilized by locality in cGMP depletion, nonlinear effects linking cGMP to current, and Ca2+ feedback arising from the physical separation of E* from the ion channels located on the outer shell, and the diffusion of these second messengers in the cytoplasm.
Collapse
|
27
|
Soto F, Tien NW, Goel A, Zhao L, Ruzycki PA, Kerschensteiner D. AMIGO2 Scales Dendrite Arbors in the Retina. Cell Rep 2019; 29:1568-1578.e4. [PMID: 31693896 PMCID: PMC6871773 DOI: 10.1016/j.celrep.2019.09.085] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2019] [Revised: 08/21/2019] [Accepted: 09/27/2019] [Indexed: 12/24/2022] Open
Abstract
The size of dendrite arbors shapes their function and differs vastly between neuron types. The signals that control dendritic arbor size remain obscure. Here, we find that in the retina, starburst amacrine cells (SACs) and rod bipolar cells (RBCs) express the homophilic cell-surface protein AMIGO2. In Amigo2 knockout (KO) mice, SAC and RBC dendrites expand while arbors of other retinal neurons remain stable. SAC dendrites are divided into a central input region and a peripheral output region that provides asymmetric inhibition to direction-selective ganglion cells (DSGCs). Input and output compartments scale precisely with increased arbor size in Amigo2 KO mice, and SAC dendrites maintain asymmetric connectivity with DSGCs. Increased coverage of SAC dendrites is accompanied by increased direction selectivity of DSGCs without changes to other ganglion cells. Our results identify AMIGO2 as a cell-type-specific dendritic scaling factor and link dendrite size and coverage to visual feature detection.
Collapse
Affiliation(s)
- Florentina Soto
- John F. Hardesty, MD Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, Saint Louis, MO 63110, USA.
| | - Nai-Wen Tien
- John F. Hardesty, MD Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, Saint Louis, MO 63110, USA; Graduate Program in Neuroscience, Washington University School of Medicine, Saint Louis, MO 63110, USA
| | - Anurag Goel
- John F. Hardesty, MD Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, Saint Louis, MO 63110, USA
| | - Lei Zhao
- John F. Hardesty, MD Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, Saint Louis, MO 63110, USA
| | - Philip A Ruzycki
- John F. Hardesty, MD Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, Saint Louis, MO 63110, USA
| | - Daniel Kerschensteiner
- John F. Hardesty, MD Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, Saint Louis, MO 63110, USA; Department of Neuroscience, Washington University School of Medicine, Saint Louis, MO 63110, USA; Department of Biomedical Engineering, Washington University School of Medicine, Saint Louis, MO 63110, USA; Hope Center for Neurological Disorders, Washington University School of Medicine, Saint Louis, MO 63110, USA.
| |
Collapse
|
28
|
Paradoxical Rules of Spike Train Decoding Revealed at the Sensitivity Limit of Vision. Neuron 2019; 104:576-587.e11. [PMID: 31519460 DOI: 10.1016/j.neuron.2019.08.005] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2018] [Revised: 05/28/2019] [Accepted: 08/03/2019] [Indexed: 12/11/2022]
Abstract
All sensory information is encoded in neural spike trains. It is unknown how the brain utilizes this neural code to drive behavior. Here, we unravel the decoding rules of the brain at the most elementary level by linking behavioral decisions to retinal output signals in a single-photon detection task. A transgenic mouse line allowed us to separate the two primary retinal outputs, ON and OFF pathways, carrying information about photon absorptions as increases and decreases in spiking, respectively. We measured the sensitivity limit of rods and the most sensitive ON and OFF ganglion cells and correlated these results with visually guided behavior using markerless head and eye tracking. We show that behavior relies only on the ON pathway even when the OFF pathway would allow higher sensitivity. Paradoxically, behavior does not rely on the spike code with maximal information but instead relies on a decoding strategy based on increases in spiking.
Collapse
|
29
|
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
|
30
|
Roy S, Field GD. Dopaminergic modulation of retinal processing from starlight to sunlight. J Pharmacol Sci 2019; 140:86-93. [PMID: 31109761 DOI: 10.1016/j.jphs.2019.03.006] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2018] [Revised: 03/13/2019] [Accepted: 03/29/2019] [Indexed: 12/17/2022] Open
Abstract
Neuromodulators such as dopamine, enable context-dependent plasticity of neural circuit function throughout the central nervous system. For example, in the retina, dopamine tunes visual processing for daylight and nightlight conditions. Specifically, high levels of dopamine release in the retina tune vision for daylight (photopic) conditions, while low levels tune it for nightlight (scotopic) conditions. This review covers the cellular and circuit-level mechanisms within the retina that are altered by dopamine. These mechanisms include changes in gap junction coupling and ionic conductances, both of which are altered by the activation of diverse types of dopamine receptors across diverse types of retinal neurons. We contextualize the modulatory actions of dopamine in terms of alterations and optimizations to visual processing under photopic and scotopic conditions, with particular attention to how they differentially impact distinct cell types. Finally, we discuss how transgenic mice and disease models have shaped our understanding of dopaminergic signaling and its role in visual processing. Cumulatively, this review illustrates some of the diverse and potent mechanisms through which neuromodulation can shape brain function.
Collapse
Affiliation(s)
- Suva Roy
- Department of Neurobiology, Duke University School of Medicine, Durham, NC, USA
| | - Greg D Field
- Department of Neurobiology, Duke University School of Medicine, Durham, NC, USA.
| |
Collapse
|
31
|
Kling A, Field GD, Brainard DH, Chichilnisky EJ. Probing Computation in the Primate Visual System at Single-Cone Resolution. Annu Rev Neurosci 2019; 42:169-186. [PMID: 30857477 DOI: 10.1146/annurev-neuro-070918-050233] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Daylight vision begins when light activates cone photoreceptors in the retina, creating spatial patterns of neural activity. These cone signals are then combined and processed in downstream neural circuits, ultimately producing visual perception. Recent technical advances have made it possible to deliver visual stimuli to the retina that probe this processing by the visual system at its elementary resolution of individual cones. Physiological recordings from nonhuman primate retinas reveal the spatial organization of cone signals in retinal ganglion cells, including how signals from cones of different types are combined to support both spatial and color vision. Psychophysical experiments with human subjects characterize the visual sensations evoked by stimulating a single cone, including the perception of color. Future combined physiological and psychophysical experiments focusing on probing the elementary visual inputs are likely to clarify how neural processing generates our perception of the visual world.
Collapse
Affiliation(s)
- A Kling
- Departments of Neurosurgery and Ophthalmology, Stanford University School of Medicine, Stanford, California 94305, USA;
| | - G D Field
- Department of Neurobiology, Duke University School of Medicine, Durham, North Carolina 27710, USA
| | - D H Brainard
- Department of Psychology, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - E J Chichilnisky
- Departments of Neurosurgery and Ophthalmology, Stanford University School of Medicine, Stanford, California 94305, USA;
| |
Collapse
|
32
|
Field GD, Uzzell V, Chichilnisky EJ, Rieke F. Temporal resolution of single-photon responses in primate rod photoreceptors and limits imposed by cellular noise. J Neurophysiol 2018; 121:255-268. [PMID: 30485153 DOI: 10.1152/jn.00683.2018] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Sensory receptor noise corrupts sensory signals, contributing to imperfect perception and dictating central processing strategies. For example, noise in rod phototransduction limits our ability to detect light, and minimizing the impact of this noise requires precisely tuned nonlinear processing by the retina. But detection sensitivity is only one aspect of night vision: prompt and accurate behavior also requires that rods reliably encode the timing of photon arrivals. We show here that the temporal resolution of responses of primate rods is much finer than the duration of the light response and identify the key limiting sources of transduction noise. We also find that the thermal activation rate of rhodopsin is lower than previous estimates, implying that other noise sources are more important than previously appreciated. A model of rod single-photon responses reveals that the limiting noise relevant for behavior depends critically on how rod signals are pooled by downstream neurons. NEW & NOTEWORTHY Many studies have focused on the visual system's ability to detect photons, but not on its ability to encode the relative timing of detected photons. Timing is essential for computations such as determining the velocity of moving objects. Here we examine the timing precision of primate rod photoreceptor responses and show that it is more precise than previously appreciated. This motivates an evaluation of whether scotopic vision approaches limits imposed by rod temporal resolution.
Collapse
Affiliation(s)
- Greg D Field
- Department of Neurobiology, Duke University School of Medicine , Durham, North Carolina
| | - Valerie Uzzell
- Systems Neurobiology Laboratories, Salk Institute for Biological Studies , La Jolla, California
| | - E J Chichilnisky
- Stanford University, Departments of Neurosurgery and Ophthalmology , Stanford, California
| | - Fred Rieke
- Department of Physiology and Biophysics, University of Washington , Seattle, Washington
| |
Collapse
|
33
|
Grimes WN, Baudin J, Azevedo AW, Rieke F. Range, routing and kinetics of rod signaling in primate retina. eLife 2018; 7:38281. [PMID: 30299254 PMCID: PMC6218188 DOI: 10.7554/elife.38281] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2018] [Accepted: 09/22/2018] [Indexed: 11/29/2022] Open
Abstract
Stimulus- or context-dependent routing of neural signals through parallel pathways can permit flexible processing of diverse inputs. For example, work in mouse shows that rod photoreceptor signals are routed through several retinal pathways, each specialized for different light levels. This light-level-dependent routing of rod signals has been invoked to explain several human perceptual results, but it has not been tested in primate retina. Here, we show, surprisingly, that rod signals traverse the primate retina almost exclusively through a single pathway – the dedicated rod bipolar pathway. Identical experiments in mouse and primate reveal substantial differences in how rod signals traverse the retina. These results require reevaluating human perceptual results in terms of flexible computation within this single pathway. This includes a prominent speeding of rod signals with light level – which we show is inherited directly from the rod photoreceptors themselves rather than from different pathways with distinct kinetics.
Collapse
Affiliation(s)
- William N Grimes
- Department of Physiology and Biophysics, University of Washington, Seattle, United States
| | - Jacob Baudin
- Department of Physiology and Biophysics, University of Washington, Seattle, United States
| | - Anthony W Azevedo
- Department of Physiology and Biophysics, University of Washington, Seattle, United States
| | - Fred Rieke
- Department of Physiology and Biophysics, University of Washington, Seattle, United States
| |
Collapse
|
34
|
Grimes WN, Songco-Aguas A, Rieke F. Parallel Processing of Rod and Cone Signals: Retinal Function and Human Perception. Annu Rev Vis Sci 2018; 4:123-141. [PMID: 29883274 PMCID: PMC6153147 DOI: 10.1146/annurev-vision-091517-034055] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
We know a good deal about the operation of the retina when either rod or cone photoreceptors provide the dominant input (i.e., under very dim or very bright conditions). However, we know much less about how the retina operates when rods and cones are coactive (i.e., under intermediate lighting conditions, such as dusk). Such mesopic conditions span 20-30% of the light levels over which vision operates and encompass many situations in which vision is essential (e.g., driving at night). These lighting conditions are challenging because rod and cone signals differ substantially: Rod responses are nearing saturation, while cone responses are weak and noisy. A rich history of perceptual studies guides our investigation of how the retina operates under mesopic conditions and in doing so provides a powerful opportunity to link general issues about parallel processing in neural circuits with computation and perception. We review some of the successes and challenges in understanding the retinal basis of perceptual rod-cone interactions.
Collapse
Affiliation(s)
- William N Grimes
- Department of Physiology and Biophysics, University of Washington, Seattle, Washington 98195, USA;
| | - Adree Songco-Aguas
- Department of Physiology and Biophysics, University of Washington, Seattle, Washington 98195, USA;
| | - Fred Rieke
- Department of Physiology and Biophysics, University of Washington, Seattle, Washington 98195, USA;
| |
Collapse
|
35
|
Abstract
A retrospective on the scientific importance and impact of Hecht, Shlaer, and Pirenne’s classic 1942 paper, “Energy, Quanta, and Vision.” Vertebrate rod photoreceptors evolved the astonishing ability to respond reliably to single photons. In parallel, the proximate neurons of the visual system evolved the ability to reliably encode information from a few single-photon responses (SPRs) as arising from the presence of an object of interest in the visual environment. These amazing capabilities were first inferred from measurements of human visual threshold by Hecht et al. (1942), whose paper has since been cited over 1,000 times. Subsequent research, in part inspired by Hecht et al.’s discovery, has directly measured rod SPRs, characterized the molecular mechanism responsible for their generation, and uncovered much about the specializations in the retina that enable the reliable transmission of SPRs in the teeth of intrinsic neuronal noise.
Collapse
|
36
|
Elgueta C, Leroy F, Vielma AH, Schmachtenberg O, Palacios AG. Electrical coupling between A17 cells enhances reciprocal inhibitory feedback to rod bipolar cells. Sci Rep 2018; 8:3123. [PMID: 29449585 PMCID: PMC5814567 DOI: 10.1038/s41598-018-21119-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2017] [Accepted: 01/29/2018] [Indexed: 11/09/2022] Open
Abstract
A17 amacrine cells are an important part of the scotopic pathway. Their synaptic varicosities receive glutamatergic inputs from rod bipolar cells (RBC) and release GABA onto the same RBC terminal, forming a reciprocal feedback that shapes RBC depolarization. Here, using patch-clamp recordings, we characterized electrical coupling between A17 cells of the rat retina and report the presence of strongly interconnected and non-coupled A17 cells. In coupled A17 cells, evoked currents preferentially flow out of the cell through GJs and cross-synchronization of presynaptic signals in a pair of A17 cells is correlated to their coupling degree. Moreover, we demonstrate that stimulation of one A17 cell can induce electrical and calcium transients in neighboring A17 cells, thus confirming a functional flow of information through electrical synapses in the A17 coupled network. Finally, blocking GJs caused a strong decrease in the amplitude of the inhibitory feedback onto RBCs. We therefore propose that electrical coupling between A17 cells enhances feedback onto RBCs by synchronizing and facilitating GABA release from inhibitory varicosities surrounding each RBC axon terminal. GJs between A17 cells are therefore critical in shaping the visual flow through the scotopic pathway.
Collapse
Affiliation(s)
- Claudio Elgueta
- Centro Interdisciplinario de Neurociencia de Valparaíso, Universidad de Valparaíso, Valparaíso, Chile.
- Physiology Institute I, Alberts Ludwig University, Freiburg, Germany.
| | - Felix Leroy
- Centro Interdisciplinario de Neurociencia de Valparaíso, Universidad de Valparaíso, Valparaíso, Chile
- Neuroscience department, Columbia University Medical Center, 1051 Riverside Drive, New York, NY, 10032, USA
| | - Alex H Vielma
- Centro Interdisciplinario de Neurociencia de Valparaíso, Universidad de Valparaíso, Valparaíso, Chile
- Physiology Institute I, Alberts Ludwig University, Freiburg, Germany
| | - Oliver Schmachtenberg
- Centro Interdisciplinario de Neurociencia de Valparaíso, Universidad de Valparaíso, Valparaíso, Chile
- Physiology Institute I, Alberts Ludwig University, Freiburg, Germany
| | - Adrian G Palacios
- Centro Interdisciplinario de Neurociencia de Valparaíso, Universidad de Valparaíso, Valparaíso, Chile
- Physiology Institute I, Alberts Ludwig University, Freiburg, Germany
| |
Collapse
|
37
|
Bókkon I, Scholkmann F, Salari V, Császár N, Kapócs G. Endogenous spontaneous ultraweak photon emission in the formation of eye-specific retinogeniculate projections before birth. Rev Neurosci 2018; 27:411-9. [PMID: 26656799 DOI: 10.1515/revneuro-2015-0051] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2015] [Accepted: 10/25/2015] [Indexed: 11/15/2022]
Abstract
In 1963, it was suggested [Sperry, R.W. (1963). Chemoaffinity in the orderly growth of nerve fiber patterns and connections. Proc. Natl. Acad. Sci. USA 50, 703-710.] that molecular cues can direct the development of orderly connections between the eye and the brain (the "chemoaffinity hypothesis"). In the same year, the amazing degree of functional accuracy of the visual pathway in the absence of any external light/photon perception prior to birth [Wiesel, T.N and Hubel, D.H. (1963). Single-cell responses in striate cortex of kittens deprived of vision in one eye. J. Neurophysiol. 26, 1003-1017.] was discovered. These recognitions revealed that the wiring of the visual system relies on innate cues. However, how the eye-specific retinogeniculate pathway can be developed before birth without any visual experience is still an unresolved issue. In the present paper, we suggest that Müller cells (functioning as optical fibers), Müller cell cone (i.e. the inner half of the foveola that is created of an inverted cone-shaped zone of Müller cells), discrete retinal noise of rods, and intrinsically photosensitive retinal ganglion cells might have key functions by means of retinal spontaneous ultraweak photon emission in the development of eye-specific retinogeniculate pathways prior to birth.
Collapse
|
38
|
Leopoldo K, Joselevitch C. A neurociência computacional no estudo dos processos cognitivos. PSICOLOGIA USP 2018. [DOI: 10.1590/0103-656420160172] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Resumo Nas últimas décadas o estudo de processos cognitivos vem sendo influenciado por duas tendências: a legitimação de diversas formas e níveis de estudo e a tentativa de integração multidisciplinar. A primeira teve grande importância na segunda metade do século XX, quando linhas de pesquisa na psicologia cognitiva e nas neurociências fortaleceram-se. Nesse sentido, destacam-se os três níveis de Marr (computacional, algorítmico e implementacional) como forma de estruturar o estudo dos processos cognitivos. A segunda tendência é mais recente e busca, apoiada na primeira, aprofundar o entendimento dos processos cognitivos em suas diversas escalas e integrar diversos paradigmas de estudos, buscando consiliência teórica. O intento deste artigo é apresentar a neurociência computacional e suas possíveis contribuições para a psicologia cognitiva, articulando, por meio dos três níveis de Marr, uma base teórica que explicite o papel de cada uma das disciplinas e as suas possíveis interações.
Collapse
|
39
|
Field GD, Sampath AP. Behavioural and physiological limits to vision in mammals. Philos Trans R Soc Lond B Biol Sci 2017; 372:rstb.2016.0072. [PMID: 28193817 DOI: 10.1098/rstb.2016.0072] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/07/2016] [Indexed: 01/22/2023] Open
Abstract
Human vision is exquisitely sensitive-a dark-adapted observer is capable of reliably detecting the absorption of a few quanta of light. Such sensitivity requires that the sensory receptors of the retina, rod photoreceptors, generate a reliable signal when single photons are absorbed. In addition, the retina must be able to extract this information and relay it to higher visual centres under conditions where very few rods signal single-photon responses while the majority generate only noise. Critical to signal transmission are mechanistic optimizations within rods and their dedicated retinal circuits that enhance the discriminability of single-photon responses by mitigating photoreceptor and synaptic noise. We describe behavioural experiments over the past century that have led to the appreciation of high sensitivity near absolute visual threshold. We further consider mechanisms within rod photoreceptors and dedicated rod circuits that act to extract single-photon responses from cellular noise. We highlight how these studies have shaped our understanding of brain function and point out several unresolved questions in the processing of light near the visual threshold.This article is part of the themed issue 'Vision in dim light'.
Collapse
Affiliation(s)
- Greg D Field
- Department of Neurobiology, Duke University School of Medicine, Durham, NC 27710, USA
| | - Alapakkam P Sampath
- Stein Eye Institute, Department of Ophthalmology, UCLA, Los Angeles, CA 90095, USA
| |
Collapse
|
40
|
Takeshita D, Smeds L, Ala-Laurila P. Processing of single-photon responses in the mammalian On and Off retinal pathways at the sensitivity limit of vision. Philos Trans R Soc Lond B Biol Sci 2017; 372:rstb.2016.0073. [PMID: 28193818 PMCID: PMC5312023 DOI: 10.1098/rstb.2016.0073] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/09/2016] [Indexed: 12/21/2022] Open
Abstract
Visually guided behaviour at its sensitivity limit relies on single-photon responses originating in a small number of rod photoreceptors. For decades, researchers have debated the neural mechanisms and noise sources that underlie this striking sensitivity. To address this question, we need to understand the constraints arising from the retinal output signals provided by distinct retinal ganglion cell types. It has recently been shown in the primate retina that On and Off parasol ganglion cells, the cell types likely to underlie light detection at the absolute visual threshold, differ fundamentally not only in response polarity, but also in the way they handle single-photon responses originating in rods. The On pathway provides the brain with a thresholded, low-noise readout and the Off pathway with a noisy, linear readout. We outline the mechanistic basis of these different coding strategies and analyse their implications for detecting the weakest light signals. We show that high-fidelity, nonlinear signal processing in the On pathway comes with costs: more single-photon responses are lost and their propagation is delayed compared with the Off pathway. On the other hand, the responses of On ganglion cells allow better intensity discrimination compared with the Off ganglion cell responses near visual threshold. This article is part of the themed issue ‘Vision in dim light’.
Collapse
Affiliation(s)
- Daisuke Takeshita
- Department of Biosciences, University of Helsinki, PO Box 65, 00014 University of Helsinki, Finland
| | - Lina Smeds
- Department of Biosciences, University of Helsinki, PO Box 65, 00014 University of Helsinki, Finland
| | - Petri Ala-Laurila
- Department of Biosciences, University of Helsinki, PO Box 65, 00014 University of Helsinki, Finland .,Department of Neuroscience and Biomedical Engineering, Aalto University School of Science, PO Box 12200, 00076 Aalto, Finland
| |
Collapse
|
41
|
Stöckl A, Smolka J, O'Carroll D, Warrant E. Resolving the Trade-off Between Visual Sensitivity and Spatial Acuity-Lessons from Hawkmoths. Integr Comp Biol 2017; 57:1093-1103. [PMID: 28992251 DOI: 10.1093/icb/icx058] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The visual systems of many animals, particularly those active during the day, are optimized for high spatial acuity. However, at night, when photons are sparse and the visual signal competes with increased noise levels, fine spatial resolution cannot be sustained and is traded-off for the greater sensitivity required to see in dim light. High spatial acuity demands detectors and successive visual processing units whose receptive fields each cover only a small area of visual space, in order to reassemble a finely sampled and well resolved image. However, the smaller the sampled area, the fewer the photons that can be collected, and thus the worse the visual sensitivity becomes-leading to the classical trade-off between sensitivity and resolution. Nocturnal animals usually resolve this trade-off in favour of sensitivity, and thus have lower spatial acuity than their diurnal counterparts. Here we review results highlighting how hawkmoths, a highly visual group of insects with species active at different light intensities, resolve the trade-off between sensitivity and spatial resolution. We compare adaptations both in the optics and retina, as well as at higher levels of neural processing in a nocturnal and a diurnal hawkmoth species, and also give a perspective on the behavioral consequences. We broaden the scope of our review by drawing comparisons with the adaptive strategies used by other nocturnal and diurnal insects.
Collapse
Affiliation(s)
- Anna Stöckl
- Department of Biology, Lund University, Lund 22362, Sweden
| | - Jochen Smolka
- Department of Biology, Lund University, Lund 22362, Sweden
| | | | - Eric Warrant
- Department of Biology, Lund University, Lund 22362, Sweden
| |
Collapse
|
42
|
Homeostatic plasticity shapes the visual system's first synapse. Nat Commun 2017; 8:1220. [PMID: 29089553 PMCID: PMC5663853 DOI: 10.1038/s41467-017-01332-7] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2016] [Accepted: 09/08/2017] [Indexed: 11/19/2022] Open
Abstract
Vision in dim light depends on synapses between rods and rod bipolar cells (RBCs). Here, we find that these synapses exist in multiple configurations, in which single release sites of rods are apposed by one to three postsynaptic densities (PSDs). Single RBCs often form multiple PSDs with one rod; and neighboring RBCs share ~13% of their inputs. Rod-RBC synapses develop while ~7% of RBCs undergo programmed cell death (PCD). Although PCD is common throughout the nervous system, its influences on circuit development and function are not well understood. We generate mice in which ~53 and ~93% of RBCs, respectively, are removed during development. In these mice, dendrites of the remaining RBCs expand in graded fashion independent of light-evoked input. As RBC dendrites expand, they form fewer multi-PSD contacts with rods. Electrophysiological recordings indicate that this homeostatic co-regulation of neurite and synapse development preserves retinal function in dim light. Retinal rod bipolar cells (RBCs) partially undergo programmed cell death triggering cell density-dependent plasticity. This study shows that increased removal of RBCs using genetic approaches causes dendrites of the remaining RBCs to expand and contact more rod photoreceptors while reducing connectivity with each.
Collapse
|
43
|
Parag KV, Vinnicombe G. Point process analysis of noise in early invertebrate vision. PLoS Comput Biol 2017; 13:e1005687. [PMID: 29077703 PMCID: PMC5678801 DOI: 10.1371/journal.pcbi.1005687] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2015] [Revised: 11/08/2017] [Accepted: 07/17/2017] [Indexed: 11/19/2022] Open
Abstract
Noise is a prevalent and sometimes even dominant aspect of many biological processes. While many natural systems have adapted to attenuate or even usefully integrate noise, the variability it introduces often still delimits the achievable precision across biological functions. This is particularly so for visual phototransduction, the process responsible for converting photons of light into usable electrical signals (quantum bumps). Here, randomness of both the photon inputs (regarded as extrinsic noise) and the conversion process (intrinsic noise) are seen as two distinct, independent and significant limitations on visual reliability. Past research has attempted to quantify the relative effects of these noise sources by using approximate methods that do not fully account for the discrete, point process and time ordered nature of the problem. As a result the conclusions drawn from these different approaches have led to inconsistent expositions of phototransduction noise performance. This paper provides a fresh and complete analysis of the relative impact of intrinsic and extrinsic noise in invertebrate phototransduction using minimum mean squared error reconstruction techniques based on Bayesian point process (Snyder) filters. An integrate-fire based algorithm is developed to reliably estimate photon times from quantum bumps and Snyder filters are then used to causally estimate random light intensities both at the front and back end of the phototransduction cascade. Comparison of these estimates reveals that the dominant noise source transitions from extrinsic to intrinsic as light intensity increases. By extending the filtering techniques to account for delays, it is further found that among the intrinsic noise components, which include bump latency (mean delay and jitter) and shape (amplitude and width) variance, it is the mean delay that is critical to noise performance. As the timeliness of visual information is important for real-time action, this delay could potentially limit the speed at which invertebrates can respond to stimuli. Consequently, if one wants to increase visual fidelity, reducing the photoconversion lag is much more important than improving the regularity of the electrical signal. The invertebrate phototransduction system captures and converts environmental light inputs into electrical signals for use in later visual processing. Consequently, one would expect it to be optimised in some way to ensure that only a minimal amount of environmental information is lost during conversion. Confirming this requires an understanding and quantification of the performance limiting noise sources. Photons, which are inherently random and discrete, introduce extrinsic noise. The phototransduction cascade, which converts photons into electrical bumps possessing non-deterministic shapes and latencies, contributes intrinsic noise. Previous work on characterising the relative impact of all these sources did not account for the discrete, causal, point process nature of the problem and thus results were often inconclusive. Here we use non-linear Poisson process filtering to show that photon noise is dominant at low light intensity and cascade noise limiting at high intensity. Further, our analysis reveals that mean bump delay is the most deleterious aspect of the intrinsic noise. Our work emphasises a new approach to assessing sensory noise and provides the first complete description and evaluation of the relative impact of noise in phototransduction that does not rely on continuity, linearity or Gaussian approximations.
Collapse
Affiliation(s)
- Kris V. Parag
- Control Group, Department of Engineering, University of Cambridge, United Kingdom
- * E-mail:
| | - Glenn Vinnicombe
- Control Group, Department of Engineering, University of Cambridge, United Kingdom
| |
Collapse
|
44
|
Salari V, Scholkmann F, Vimal RLP, Császár N, Aslani M, Bókkon I. Phosphenes, retinal discrete dark noise, negative afterimages and retinogeniculate projections: A new explanatory framework based on endogenous ocular luminescence. Prog Retin Eye Res 2017; 60:101-119. [DOI: 10.1016/j.preteyeres.2017.07.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2017] [Revised: 07/13/2017] [Accepted: 07/15/2017] [Indexed: 02/07/2023]
|
45
|
Zylberberg J, Strowbridge BW. Mechanisms of Persistent Activity in Cortical Circuits: Possible Neural Substrates for Working Memory. Annu Rev Neurosci 2017; 40:603-627. [PMID: 28772102 PMCID: PMC5995341 DOI: 10.1146/annurev-neuro-070815-014006] [Citation(s) in RCA: 113] [Impact Index Per Article: 16.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
A commonly observed neural correlate of working memory is firing that persists after the triggering stimulus disappears. Substantial effort has been devoted to understanding the many potential mechanisms that may underlie memory-associated persistent activity. These rely either on the intrinsic properties of individual neurons or on the connectivity within neural circuits to maintain the persistent activity. Nevertheless, it remains unclear which mechanisms are at play in the many brain areas involved in working memory. Herein, we first summarize the palette of different mechanisms that can generate persistent activity. We then discuss recent work that asks which mechanisms underlie persistent activity in different brain areas. Finally, we discuss future studies that might tackle this question further. Our goal is to bridge between the communities of researchers who study either single-neuron biophysical, or neural circuit, mechanisms that can generate the persistent activity that underlies working memory.
Collapse
Affiliation(s)
- Joel Zylberberg
- Department of Physiology and Biophysics, Center for Neuroscience, and Computational Bioscience Program, University of Colorado School of Medicine, Aurora, Colorado 80045
- Department of Applied Mathematics, University of Colorado, Boulder, Colorado 80309
- Learning in Machines and Brains Program, Canadian Institute for Advanced Research, Toronto, Ontario M5G 1Z8, Canada
| | - Ben W Strowbridge
- Department of Neurosciences, Case Western Reserve University School of Medicine, Cleveland, Ohio 44106;
- Department of Physiology and Biophysics, Case Western Reserve University School of Medicine, Cleveland, Ohio 44106
| |
Collapse
|
46
|
Martemyanov KA, Sampath AP. The Transduction Cascade in Retinal ON-Bipolar Cells: Signal Processing and Disease. Annu Rev Vis Sci 2017; 3:25-51. [PMID: 28715957 DOI: 10.1146/annurev-vision-102016-061338] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Our robust visual experience is based on the reliable transfer of information from our photoreceptor cells, the rods and cones, to higher brain centers. At the very first synapse of the visual system, information is split into two separate pathways, ON and OFF, which encode increments and decrements in light intensity, respectively. The importance of this segregation is borne out in the fact that receptive fields in higher visual centers maintain a separation between ON and OFF regions. In the past decade, the molecular mechanisms underlying the generation of ON signals have been identified, which are unique in their use of a G-protein signaling cascade. In this review, we consider advances in our understanding of G-protein signaling in ON-bipolar cell (BC) dendrites and how insights about signaling have emerged from visual deficits, mostly night blindness. Studies of G-protein signaling in ON-BCs reveal an intricate mechanism that permits the regulation of visual sensitivity over a wide dynamic range.
Collapse
Affiliation(s)
| | - Alapakkam P Sampath
- Jules Stein Eye Institute, University of California, Los Angeles, California 90095;
| |
Collapse
|
47
|
Tian H, Sakmar TP, Huber T. Measurement of Slow Spontaneous Release of 11-cis-Retinal from Rhodopsin. Biophys J 2017; 112:153-161. [PMID: 28076806 DOI: 10.1016/j.bpj.2016.12.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2016] [Revised: 11/08/2016] [Accepted: 12/05/2016] [Indexed: 01/05/2023] Open
Abstract
The vertebrate visual photoreceptor rhodopsin (Rho) is a unique G protein-coupled receptor as it utilizes a covalently tethered inverse agonist (11-cis-retinal) as the native ligand. Previously, electrophysiological studies showed that ligand binding of 11-cis-retinal in dark-adapted Rho was essentially irreversible with a half-life estimated to be 420 years, until after thermal isomerization to all-trans-retinal, which then slowly dissociates. This long lifetime of 11-cis-retinal binding was considered to be physiologically important for minimizing background signal (dark noise) of the visual system. However, in vitro biochemical studies on the thermal stability of Rho showed that Rho decays with a half-life on the order of days. In this study, we resolve the discrepancy by measuring the chromophore exchange rate of the bound 11-cis-retinal chromophore with free 9-cis-retinal from Rho in an in vitro phospholipid/detergent bicelle system. We conclude that the thermal decay of Rho primarily proceeds through spontaneous breaking of the covalent linkage between opsin and 11-cis-retinal, which was overlooked in the electrophysiological recording. We estimate that this slow spontaneous release of 11-cis-retinal from Rho should result in 104 to 105 free opsin molecules in a dark-adapted rod cell-a number that is three orders of magnitude higher than previously expected. We also discuss the physiological implications of these findings on the basal activity of opsins and the associated dark noise in the visual system.
Collapse
Affiliation(s)
- He Tian
- Laboratory of Chemical Biology and Signal Transduction, The Rockefeller University, New York, NY
| | - Thomas P Sakmar
- Laboratory of Chemical Biology and Signal Transduction, The Rockefeller University, New York, NY; Department of Neurobiology, Care Sciences and Society, Division of Neurogeriatrics, Center for Alzheimer Research, Karolinska Institutet, Huddinge, Sweden.
| | - Thomas Huber
- Laboratory of Chemical Biology and Signal Transduction, The Rockefeller University, New York, NY.
| |
Collapse
|
48
|
Astakhova LA, Nikolaeva DA, Fedotkina TV, Govardovskii VI, Firsov ML. Elevated cAMP improves signal-to-noise ratio in amphibian rod photoreceptors. J Gen Physiol 2017; 149:689-701. [PMID: 28611079 PMCID: PMC5496506 DOI: 10.1085/jgp.201611744] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2016] [Accepted: 05/31/2017] [Indexed: 11/20/2022] Open
Abstract
Vertebrate photoreceptors need to distinguish light signals from background noise to convey visual information to downstream bipolar cells. By affecting both signal and noise, Astakhova et al. find that increases in intracellular cAMP can improve the signal-to-noise ratio by twofold. The absolute sensitivity of vertebrate retinas is set by a background noise, called dark noise, which originates from several different cell types and is generated by different molecular mechanisms. The major share of dark noise is produced by photoreceptors and consists of two components, discrete and continuous. Discrete noise is generated by spontaneous thermal activations of visual pigment. These events are undistinguishable from real single-photon responses (SPRs) and might be considered an equivalent of the signal. Continuous noise is produced by spontaneous fluctuations of the catalytic activity of the cGMP phosphodiesterase. This masks both SPR and spontaneous SPR-like responses. Circadian rhythms affect photoreceptors, among other systems by periodically increasing intracellular cAMP levels ([cAMP]in), which increases the size and changes the shape of SPRs. Here, we show that forskolin, a tool that increases [cAMP]in, affects the magnitude and frequency spectrum of the continuous and discrete components of dark noise in photoreceptors. By changing both components of rod signaling, the signal and the noise, cAMP is able to increase the photoreceptor signal-to-noise ratio by twofold. We propose that this results in a substantial improvement of signal detection, without compromising noise rejection, at the rod bipolar cell synapse.
Collapse
Affiliation(s)
- Luba A Astakhova
- Sechenov Institute for Evolutionary Physiology and Biochemistry, Russian Academy of Science, St. Petersburg, Russia
| | - Darya A Nikolaeva
- Sechenov Institute for Evolutionary Physiology and Biochemistry, Russian Academy of Science, St. Petersburg, Russia
| | - Tamara V Fedotkina
- Sechenov Institute for Evolutionary Physiology and Biochemistry, Russian Academy of Science, St. Petersburg, Russia
| | - Victor I Govardovskii
- Sechenov Institute for Evolutionary Physiology and Biochemistry, Russian Academy of Science, St. Petersburg, Russia
| | - Michael L Firsov
- Sechenov Institute for Evolutionary Physiology and Biochemistry, Russian Academy of Science, St. Petersburg, Russia
| |
Collapse
|
49
|
Adaptation of cone pigments found in green rods for scotopic vision through a single amino acid mutation. Proc Natl Acad Sci U S A 2017; 114:5437-5442. [PMID: 28484015 DOI: 10.1073/pnas.1620010114] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Most vertebrate retinas contain a single type of rod for scotopic vision and multiple types of cones for photopic and color vision. The retinas of certain amphibian species uniquely contain two types of rods: red rods, which express rhodopsin, and green rods, which express a blue-sensitive cone pigment (M1/SWS2 group). Spontaneous activation of rhodopsin induced by thermal isomerization of the retinal chromophore has been suggested to contribute to the rod's background noise, which limits the visual threshold for scotopic vision. Therefore, rhodopsin must exhibit low thermal isomerization rate compared with cone visual pigments to adapt to scotopic condition. In this study, we determined whether amphibian blue-sensitive cone pigments in green rods exhibit low thermal isomerization rates to act as rhodopsin-like pigments for scotopic vision. Anura blue-sensitive cone pigments exhibit low thermal isomerization rates similar to rhodopsin, whereas Urodela pigments exhibit high rates like other vertebrate cone pigments present in cones. Furthermore, by mutational analysis, we identified a key amino acid residue, Thr47, that is responsible for the low thermal isomerization rates of Anura blue-sensitive cone pigments. These results strongly suggest that, through this mutation, anurans acquired special blue-sensitive cone pigments in their green rods, which could form the molecular basis for scotopic color vision with normal red rods containing green-sensitive rhodopsin.
Collapse
|
50
|
Brinkman BAW, Weber AI, Rieke F, Shea-Brown E. How Do Efficient Coding Strategies Depend on Origins of Noise in Neural Circuits? PLoS Comput Biol 2016; 12:e1005150. [PMID: 27741248 PMCID: PMC5065234 DOI: 10.1371/journal.pcbi.1005150] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2016] [Accepted: 09/16/2016] [Indexed: 11/18/2022] Open
Abstract
Neural circuits reliably encode and transmit signals despite the presence of noise at multiple stages of processing. The efficient coding hypothesis, a guiding principle in computational neuroscience, suggests that a neuron or population of neurons allocates its limited range of responses as efficiently as possible to best encode inputs while mitigating the effects of noise. Previous work on this question relies on specific assumptions about where noise enters a circuit, limiting the generality of the resulting conclusions. Here we systematically investigate how noise introduced at different stages of neural processing impacts optimal coding strategies. Using simulations and a flexible analytical approach, we show how these strategies depend on the strength of each noise source, revealing under what conditions the different noise sources have competing or complementary effects. We draw two primary conclusions: (1) differences in encoding strategies between sensory systems-or even adaptational changes in encoding properties within a given system-may be produced by changes in the structure or location of neural noise, and (2) characterization of both circuit nonlinearities as well as noise are necessary to evaluate whether a circuit is performing efficiently.
Collapse
Affiliation(s)
- Braden A W Brinkman
- Department of Applied Mathematics, University of Washington, Seattle, Washington, United States of America.,Department of Physiology and Biophysics, University of Washington, Seattle, Washington, United States of America
| | - Alison I Weber
- Department of Applied Mathematics, University of Washington, Seattle, Washington, United States of America.,Department of Physiology and Biophysics, University of Washington, Seattle, Washington, United States of America.,Graduate Program in Neuroscience, University of Washington, Seattle, Washington, United States of America
| | - Fred Rieke
- Department of Physiology and Biophysics, University of Washington, Seattle, Washington, United States of America.,Graduate Program in Neuroscience, University of Washington, Seattle, Washington, United States of America.,Howard Hughes Medical Institute, University of Washington, Seattle, Washington, United States of America
| | - Eric Shea-Brown
- Department of Applied Mathematics, University of Washington, Seattle, Washington, United States of America.,Department of Physiology and Biophysics, University of Washington, Seattle, Washington, United States of America.,Graduate Program in Neuroscience, University of Washington, Seattle, Washington, United States of America
| |
Collapse
|