1
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Gangi M, Maruyama T, Ishii T, Kaneda M. ON and OFF starburst amacrine cells are controlled by distinct cholinergic pathways. J Gen Physiol 2024; 156:e202413550. [PMID: 38836782 PMCID: PMC11153316 DOI: 10.1085/jgp.202413550] [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: 02/08/2024] [Revised: 04/19/2024] [Accepted: 05/27/2024] [Indexed: 06/06/2024] Open
Abstract
Cholinergic signaling in the retina is mediated by acetylcholine (ACh) released from starburst amacrine cells (SACs), which are key neurons for motion detection. SACs comprise ON and OFF subtypes, which morphologically show mirror symmetry to each other. Although many physiological studies on SACs have targeted ON cells only, the synaptic computation of ON and OFF SACs is assumed to be similar. Recent studies demonstrated that gene expression patterns and receptor types differed between ON and OFF SACs, suggesting differences in their functions. Here, we compared cholinergic signaling pathways between ON and OFF SACs in the mouse retina using the patch clamp technique. The application of ACh increased GABAergic feedback, observed as postsynaptic currents to SACs, in both ON and OFF SACs; however, the mode of GABAergic feedback differed. Nicotinic receptors mediated GABAergic feedback in both ON and OFF SACs, while muscarinic receptors mediated GABAergic feedback in ON SACs only in adults. Neither tetrodotoxin, which blocked action potentials, nor LY354740, which blocked neurotransmitter release from SACs, eliminated ACh-induced GABAergic feedback in SACs. These results suggest that ACh-induced GABAergic feedback in ON and OFF SACs is regulated by different feedback mechanisms in adults and mediated by non-spiking amacrine cells other than SACs.
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Affiliation(s)
- Mie Gangi
- Department of Physiology, Nippon Medical School, Tokyo, Japan
| | - Takuma Maruyama
- Department of Physiology, Nippon Medical School, Tokyo, Japan
| | - Toshiyuki Ishii
- Department of Physiology, Nippon Medical School, Tokyo, Japan
| | - Makoto Kaneda
- Department of Physiology, Nippon Medical School, Tokyo, Japan
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2
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Friedrichsen K, Hsiang JC, Lin CI, McCoy L, Valkova K, Kerschensteiner D, Morgan JL. Subcellular pathways through VGluT3-expressing mouse amacrine cells provide locally tuned object-motion-selective signals in the retina. Nat Commun 2024; 15:2965. [PMID: 38580652 PMCID: PMC10997783 DOI: 10.1038/s41467-024-46996-0] [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: 06/19/2023] [Accepted: 03/15/2024] [Indexed: 04/07/2024] Open
Abstract
VGluT3-expressing mouse retinal amacrine cells (VG3s) respond to small-object motion and connect to multiple types of bipolar cells (inputs) and retinal ganglion cells (RGCs, outputs). Because these input and output connections are intermixed on the same dendrites, making sense of VG3 circuitry requires comparing the distribution of synapses across their arbors to the subcellular flow of signals. Here, we combine subcellular calcium imaging and electron microscopic connectomic reconstruction to analyze how VG3s integrate and transmit visual information. VG3s receive inputs from all nearby bipolar cell types but exhibit a strong preference for the fast type 3a bipolar cells. By comparing input distributions to VG3 dendrite responses, we show that VG3 dendrites have a short functional length constant that likely depends on inhibitory shunting. This model predicts that RGCs that extend dendrites into the middle layers of the inner plexiform encounter VG3 dendrites whose responses vary according to the local bipolar cell response type.
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Affiliation(s)
- Karl Friedrichsen
- Department of Ophthalmology and Visual Sciences, Washington University in St. Louis, St. Louis, MO, USA
- Department of Neuroscience, Washington University in St. Louis, St. Louis, MO, USA
- Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, MO, USA
- Graduate Program in Neuroscience, Washington University in St. Louis, St. Louis, USA
| | - Jen-Chun Hsiang
- Department of Ophthalmology and Visual Sciences, Washington University in St. Louis, St. Louis, MO, USA
- Department of Neuroscience, Washington University in St. Louis, St. Louis, MO, USA
- Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, MO, USA
- Graduate Program in Neuroscience, Washington University in St. Louis, St. Louis, USA
| | - Chin-I Lin
- Department of Ophthalmology and Visual Sciences, Washington University in St. Louis, St. Louis, MO, USA
- Department of Neuroscience, Washington University in St. Louis, St. Louis, MO, USA
- Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, MO, USA
- Graduate Program in Neuroscience, Washington University in St. Louis, St. Louis, USA
| | - Liam McCoy
- Department of Ophthalmology and Visual Sciences, Washington University in St. Louis, St. Louis, MO, USA
- Department of Neuroscience, Washington University in St. Louis, St. Louis, MO, USA
- Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, MO, USA
| | - Katia Valkova
- Department of Ophthalmology and Visual Sciences, Washington University in St. Louis, St. Louis, MO, USA
- Department of Neuroscience, Washington University in St. Louis, St. Louis, MO, USA
- Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, MO, USA
| | - Daniel Kerschensteiner
- Department of Ophthalmology and Visual Sciences, Washington University in St. Louis, St. Louis, MO, USA.
- Department of Neuroscience, Washington University in St. Louis, St. Louis, MO, USA.
- Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, MO, USA.
| | - Josh L Morgan
- Department of Ophthalmology and Visual Sciences, Washington University in St. Louis, St. Louis, MO, USA.
- Department of Neuroscience, Washington University in St. Louis, St. Louis, MO, USA.
- Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, MO, USA.
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3
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Kim D, Roh H, Lee HM, Kim SJ, Im M. Localization of hyperpolarization-activated cyclic nucleotide-gated channels in the vertebrate retinas across species and their physiological roles. Front Neuroanat 2024; 18:1385932. [PMID: 38562955 PMCID: PMC10982330 DOI: 10.3389/fnana.2024.1385932] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2024] [Accepted: 03/06/2024] [Indexed: 04/04/2024] Open
Abstract
Transmembrane proteins known as hyperpolarization-activated cyclic nucleotide-gated (HCN) channels control the movement of Na+ and K+ ions across cellular membranes. HCN channels are known to be involved in crucial physiological functions in regulating neuronal excitability and rhythmicity, and pacemaker activity in the heart. Although HCN channels have been relatively well investigated in the brain, their distribution and function in the retina have received less attention, remaining their physiological roles to be comprehensively understood. Also, because recent studies reported HCN channels have been somewhat linked with the dysfunction of photoreceptors which are affected by retinal diseases, investigating HCN channels in the retina may offer valuable insights into disease mechanisms and potentially contribute to identifying novel therapeutic targets for retinal degenerative disorders. This paper endeavors to summarize the existing literature on the distribution and function of HCN channels reported in the vertebrate retinas of various species and discuss the potential implications for the treatment of retinal diseases. Then, we recapitulate current knowledge regarding the function and regulation of HCN channels, as well as their relevance to various neurological disorders.
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Affiliation(s)
- Daniel Kim
- Brain Science Institute, Korea Institute of Science and Technology (KIST), Seoul, Republic of Korea
- Department of Biomedical Sciences, College of Medicine, Seoul National University (SNU), Seoul, Republic of Korea
| | - Hyeonhee Roh
- School of Electrical Engineering, College of Engineering, Korea University, Seoul, Republic of Korea
| | - Hyung-Min Lee
- School of Electrical Engineering, College of Engineering, Korea University, Seoul, Republic of Korea
| | - Sang Jeong Kim
- Department of Biomedical Sciences, College of Medicine, Seoul National University (SNU), Seoul, Republic of Korea
| | - Maesoon Im
- Brain Science Institute, Korea Institute of Science and Technology (KIST), Seoul, Republic of Korea
- Division of Bio-Medical Science & Technology, KIST School, University of Science & Technology (UST), Seoul, Republic of Korea
- KHU-KIST Department of Converging Science and Technology, Kyung Hee University, Seoul, Republic of Korea
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4
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Hsiang JC, Shen N, Soto F, Kerschensteiner D. Distributed feature representations of natural stimuli across parallel retinal pathways. Nat Commun 2024; 15:1920. [PMID: 38429280 PMCID: PMC10907388 DOI: 10.1038/s41467-024-46348-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: 08/10/2023] [Accepted: 02/22/2024] [Indexed: 03/03/2024] Open
Abstract
How sensory systems extract salient features from natural environments and organize them across neural pathways is unclear. Combining single-cell and population two-photon calcium imaging in mice, we discover that retinal ON bipolar cells (second-order neurons of the visual system) are divided into two blocks of four types. The two blocks distribute temporal and spatial information encoding, respectively. ON bipolar cell axons co-stratify within each block, but separate laminarly between them (upper block: diverse temporal, uniform spatial tuning; lower block: diverse spatial, uniform temporal tuning). ON bipolar cells extract temporal and spatial features similarly from artificial and naturalistic stimuli. In addition, they differ in sensitivity to coherent motion in naturalistic movies. Motion information is distributed across ON bipolar cells in the upper and the lower blocks, multiplexed with temporal and spatial contrast, independent features of natural scenes. Comparing the responses of different boutons within the same arbor, we find that axons of all ON bipolar cell types function as computational units. Thus, our results provide insights into the visual feature extraction from naturalistic stimuli and reveal how structural and functional organization cooperate to generate parallel ON pathways for temporal and spatial information in the mammalian retina.
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Affiliation(s)
- Jen-Chun Hsiang
- Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, St. Louis, MO, 63110, USA
| | - Ning Shen
- Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, St. Louis, MO, 63110, USA
| | - Florentina Soto
- Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, St. Louis, MO, 63110, USA
| | - Daniel Kerschensteiner
- Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, St. Louis, MO, 63110, USA.
- Department of Neuroscience, Washington University School of Medicine, St. Louis, MO, 63110, USA.
- Department of Biomedical Engineering, Washington University School of Medicine, St. Louis, MO, 63110, USA.
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5
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Balaji V, Haverkamp S, Seth PK, Günther A, Mendoza E, Schmidt J, Herrmann M, Pfeiffer LL, Němec P, Scharff C, Mouritsen H, Dedek K. Immunohistochemical characterization of bipolar cells in four distantly related avian species. J Comp Neurol 2023; 531:561-581. [PMID: 36550622 DOI: 10.1002/cne.25443] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2022] [Revised: 11/29/2022] [Accepted: 12/01/2022] [Indexed: 12/24/2022]
Abstract
Visual (and probably also magnetic) signal processing starts at the first synapse, at which photoreceptors contact different types of bipolar cells, thereby feeding information into different processing channels. In the chicken retina, 15 and 22 different bipolar cell types have been identified based on serial electron microscopy and single-cell transcriptomics, respectively. However, immunohistochemical markers for avian bipolar cells were only anecdotally described so far. Here, we systematically tested 12 antibodies for their ability to label individual bipolar cells in the bird retina and compared the eight most suitable antibodies across distantly related species, namely domestic chicken, domestic pigeon, common buzzard, and European robin, and across retinal regions. While two markers (GNB3 and EGFR) labeled specifically ON bipolar cells, most markers labeled in addition to bipolar cells also other cell types in the avian retina. Staining pattern of four markers (CD15, PKCα, PKCβ, secretagogin) was species-specific. Two markers (calbindin and secretagogin) showed a different expression pattern in central and peripheral retina. For the chicken and European robin, we found slightly more ON bipolar cell somata in the inner nuclear layer than OFF bipolar cell somata. In contrast, OFF bipolar cells made more ribbon synapses than ON bipolar cells in the inner plexiform layer of these species. Finally, we also analyzed the photoreceptor connectivity of selected bipolar cell types in the European robin retina. In summary, we provide a catalog of bipolar cell markers for different bird species, which will greatly facilitate analyzing the retinal circuitry of birds on a larger scale.
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Affiliation(s)
- Vaishnavi Balaji
- Animal Navigation/Neurosensorics Group, Institute for Biology and Environmental Sciences, University of Oldenburg, Oldenburg, Germany
| | - Silke Haverkamp
- Department Computational Neuroethology, Max Planck Institute for Neurobiology of Behavior - caesar, Bonn, Germany
| | - Pranav Kumar Seth
- Animal Navigation/Neurosensorics Group, Institute for Biology and Environmental Sciences, University of Oldenburg, Oldenburg, Germany
| | - Anja Günther
- Animal Navigation/Neurosensorics Group, Institute for Biology and Environmental Sciences, University of Oldenburg, Oldenburg, Germany.,Department Computational Neuroethology, Max Planck Institute for Neurobiology of Behavior - caesar, Bonn, Germany
| | - Ezequiel Mendoza
- Institut für Biologie, Freie Universität Berlin, Berlin, Germany
| | - Jessica Schmidt
- Animal Navigation/Neurosensorics Group, Institute for Biology and Environmental Sciences, University of Oldenburg, Oldenburg, Germany
| | - Maike Herrmann
- Animal Navigation/Neurosensorics Group, Institute for Biology and Environmental Sciences, University of Oldenburg, Oldenburg, Germany
| | - Leonie Lovis Pfeiffer
- Animal Navigation/Neurosensorics Group, Institute for Biology and Environmental Sciences, University of Oldenburg, Oldenburg, Germany
| | - Pavel Němec
- Department of Zoology, Charles University, Prague, Czech Republic
| | | | - Henrik Mouritsen
- Animal Navigation/Neurosensorics Group, Institute for Biology and Environmental Sciences, University of Oldenburg, Oldenburg, Germany.,Research Center Neurosensory Science, University of Oldenburg, Oldenburg, Germany
| | - Karin Dedek
- Animal Navigation/Neurosensorics Group, Institute for Biology and Environmental Sciences, University of Oldenburg, Oldenburg, Germany.,Research Center Neurosensory Science, University of Oldenburg, Oldenburg, Germany
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6
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Fournel R, Veruki ML, Hartveit E. Digital reconstruction and quantitative morphometric analysis of bipolar cells in live rat retinal slices. J Comp Neurol 2022; 530:1700-1728. [PMID: 35152437 PMCID: PMC9310816 DOI: 10.1002/cne.25308] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2021] [Revised: 01/06/2022] [Accepted: 01/27/2022] [Indexed: 11/27/2022]
Abstract
Bipolar cells convey signals from photoreceptors in the outer retina to amacrine and ganglion cells in the inner retina. In mammals, there are typically 10–15 types of cone bipolar cells and one type of rod bipolar cell. Different types of cone bipolar cells are thought to code and transmit different features of a complex visual stimulus, thereby generating parallel channels that uniquely filter and transform the photoreceptor outputs. Differential synaptic connectivity and expression of ligand‐ and voltage‐gated ion channels are thought to be important mechanisms for processing and filtering visual signals. Whereas the biophysical basis for such mechanisms has been investigated more extensively in rat retina, there is a lack of quantitative morphological data necessary for advancing the structure–function correlation in this species, as recent connectomics investigations have focused on mouse retina. Here, we performed whole‐cell recordings from cone and rod bipolar cells in rat retinal slices, filled the cells with fluorescent dyes, and acquired image stacks by multiphoton excitation microscopy. Following deconvolution, we performed digital reconstruction and morphometric analysis of 25 cone and 14 rod bipolar cells. Compared to previous descriptions, the extent and complexity of branching of the axon terminal was surprisingly high. By precisely quantifying the level of stratification of the axon terminals in the inner plexiform layer, we have generated a reference system for reliable classification of individual cells in future studies focused on correlating physiological and morphological properties. The implemented workflow can be extended to the development of morphologically realistic compartmental models for these neurons.
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Affiliation(s)
- Rémi Fournel
- University of Bergen Department of Biomedicine Bergen Norway
| | | | - Espen Hartveit
- University of Bergen Department of Biomedicine Bergen Norway
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7
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Sharpe ZJ, Shehu A, Ichinose T. Asymmetric Distributions of Achromatic Bipolar Cells in the Mouse Retina. Front Neuroanat 2022; 15:786142. [PMID: 35095431 PMCID: PMC8792968 DOI: 10.3389/fnana.2021.786142] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Accepted: 12/13/2021] [Indexed: 11/23/2022] Open
Abstract
In the retina, evolutionary changes can be traced in the topography of photoreceptors. The shape of the visual streak depends on the height of the animal and its habitat, namely, woods, prairies, or mountains. Also, the distribution of distinct wavelength-sensitive cones is unique to each animal. For example, UV and green cones reside in the ventral and dorsal regions in the mouse retina, respectively, whereas in the rat retina these cones are homogeneously distributed. In contrast with the abundant investigation on the distribution of photoreceptors and the third-order neurons, the distribution of bipolar cells has not been well understood. We utilized two enhanced green fluorescent protein (EGFP) mouse lines, Lhx4-EGFP (Lhx4) and 6030405A18Rik-EGFP (Rik), to examine the topographic distributions of bipolar cells in the retina. First, we characterized their GFP-expressing cells using type-specific markers. We found that GFP was expressed by type 2, type 3a, and type 6 bipolar cells in the Rik mice and by type 3b, type 4, and type 5 bipolar cells in the Lhx4 mice. All these types are achromatic. Then, we examined the distributions of bipolar cells in the four cardinal directions and three different eccentricities of the retinal tissue. In the Rik mice, GFP-expressing bipolar cells were more highly observed in the nasal region than those in the temporal retina. The number of GFP cells was not different along with the ventral-dorsal axis. In contrast, in the Lhx4 mice, GFP-expressing cells occurred at a higher density in the ventral region than in the dorsal retina. However, no difference was observed along the nasal-temporal axis. Furthermore, we examined which type of bipolar cells contributed to the asymmetric distributions in the Rik mice. We found that type 3a bipolar cells occurred at a higher density in the temporal region, whereas type 6 bipolar cells were denser in the nasal region. The asymmetricity of these bipolar cells shaped the uneven distribution of the GFP cells in the Rik mice. In conclusion, we found that a subset of achromatic bipolar cells is asymmetrically distributed in the mouse retina, suggesting their unique roles in achromatic visual processing.
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8
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Paknahad J, Kosta P, Bouteiller JMC, Humayun MS, Lazzi G. Mechanisms underlying activation of retinal bipolar cells through targeted electrical stimulation: a computational study. J Neural Eng 2021; 18. [PMID: 34826830 DOI: 10.1088/1741-2552/ac3dd8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2021] [Accepted: 11/26/2021] [Indexed: 11/12/2022]
Abstract
Objective. Retinal implants have been developed to electrically stimulate healthy retinal neurons in the progressively degenerated retina. Several stimulation approaches have been proposed to improve the visual percept induced in patients with retinal prostheses. We introduce a computational model capable of simulating the effects of electrical stimulation on retinal neurons. Leveraging this computational platform, we delve into the underlying mechanisms influencing the sensitivity of retinal neurons' response to various stimulus waveforms.Approach. We implemented a model of spiking bipolar cells (BCs) in the magnocellular pathway of the primate retina, diffuse BC subtypes (DB4), and utilized our multiscale admittance method (AM)-NEURON computational platform to characterize the response of BCs to epiretinal electrical stimulation with monophasic, symmetric, and asymmetric biphasic pulses.Main results. Our investigations yielded four notable results: (a) the latency of BCs increases as stimulation pulse duration lengthens; conversely, this latency decreases as the current amplitude increases. (b) Stimulation with a long anodic-first symmetric biphasic pulse (duration > 8 ms) results in a significant decrease in spiking threshold compared to stimulation with similar cathodic-first pulses (from 98.2 to 57.5µA). (c) The hyperpolarization-activated cyclic nucleotide-gated channel was a prominent contributor to the reduced threshold of BCs in response to long anodic-first stimulus pulses. (d) Finally, extending the study to asymmetric waveforms, our results predict a lower BCs threshold using asymmetric long anodic-first pulses compared to that of asymmetric short cathodic-first stimulation.Significance. This study predicts the effects of several stimulation parameters on spiking BCs response to electrical stimulation. Of importance, our findings shed light on mechanisms underlying the experimental observations from the literature, thus highlighting the capability of the methodology to predict and guide the development of electrical stimulation protocols to generate a desired biological response, thereby constituting an ideal testbed for the development of electroceutical devices.
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Affiliation(s)
- Javad Paknahad
- Department of Electrical and Computer Engineering, University of Southern California, Los Angeles, CA, United States of America.,Institute for Technology and Medical Systems (ITEMS), Keck School of Medicine, University of Southern California, Los Angeles, CA, United States of America
| | - Pragya Kosta
- Institute for Technology and Medical Systems (ITEMS), Keck School of Medicine, University of Southern California, Los Angeles, CA, United States of America
| | - Jean-Marie C Bouteiller
- Department of Biomedical Engineering, University of Southern California, Los Angeles, CA, United States of America
| | - Mark S Humayun
- Department of Biomedical Engineering, University of Southern California, Los Angeles, CA, United States of America.,Department of Ophthalmology, University of Southern California, Los Angeles, CA, United States of America
| | - Gianluca Lazzi
- Department of Electrical and Computer Engineering, University of Southern California, Los Angeles, CA, United States of America.,Institute for Technology and Medical Systems (ITEMS), Keck School of Medicine, University of Southern California, Los Angeles, CA, United States of America.,Department of Biomedical Engineering, University of Southern California, Los Angeles, CA, United States of America.,Department of Ophthalmology, University of Southern California, Los Angeles, CA, United States of America
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9
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Hellmer CB, Hall LM, Bohl JM, Sharpe ZJ, Smith RG, Ichinose T. Cholinergic feedback to bipolar cells contributes to motion detection in the mouse retina. Cell Rep 2021; 37:110106. [PMID: 34910920 PMCID: PMC8793255 DOI: 10.1016/j.celrep.2021.110106] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2021] [Revised: 08/11/2021] [Accepted: 11/16/2021] [Indexed: 11/25/2022] Open
Abstract
Retinal bipolar cells are second-order neurons that transmit basic features of the visual scene to postsynaptic partners. However, their contribution to motion detection has not been fully appreciated. Here, we demonstrate that cholinergic feedback from starburst amacrine cells (SACs) to certain presynaptic bipolar cells via alpha-7 nicotinic acetylcholine receptors (α7-nAChRs) promotes direction-selective signaling. Patch clamp recordings reveal that distinct bipolar cell types making synapses at proximal SAC dendrites also express α7-nAChRs, producing directionally skewed excitatory inputs. Asymmetric SAC excitation contributes to motion detection in On-Off direction-selective ganglion cells (On-Off DSGCs), predicted by computational modeling of SAC dendrites and supported by patch clamp recordings from On-Off DSGCs when bipolar cell α7-nAChRs is eliminated pharmacologically or by conditional knockout. Altogether, these results show that cholinergic feedback to bipolar cells enhances direction-selective signaling in postsynaptic SACs and DSGCs, illustrating how bipolar cells provide a scaffold for postsynaptic microcircuits to cooperatively enhance retinal motion detection.
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Affiliation(s)
- Chase B Hellmer
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, Detroit, MI 48201, USA; Present address: Department of Ophthalmology and Visual Sciences, University of Louisville, Louisville, KY 40202, USA
| | - Leo M Hall
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, Detroit, MI 48201, USA; Present address: Department of Internal Medicine, St. Mary Mercy Livonia Hospital, Livonia, MI 48154, USA
| | - Jeremy M Bohl
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, Detroit, MI 48201, USA
| | - Zachary J Sharpe
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, Detroit, MI 48201, USA
| | - Robert G Smith
- Department of Neuroscience, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Tomomi Ichinose
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, Detroit, MI 48201, USA.
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10
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Liu JH, Singh JB, Veruki ML, Hartveit E. Morphological properties of the axon initial segment-like process of AII amacrine cells in the rat retina. J Comp Neurol 2021; 529:3593-3620. [PMID: 34219229 DOI: 10.1002/cne.25210] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2021] [Revised: 06/28/2021] [Accepted: 06/30/2021] [Indexed: 12/24/2022]
Abstract
Signal processing within the retina is generally mediated by graded potentials, whereas output is conveyed by action potentials transmitted along optic nerve axons. Among retinal neurons, amacrine cells seem to be an exception to this general rule, as several types generate voltage-gated Na+ (Nav ) channel-dependent action potentials. The AII, a narrow-field, bistratified axon-less amacrine cell found in mammalian retinas, displays a unique process that resembles an axon initial segment (AIS), with expression of Nav channels colocalized with the cytoskeletal protein ankyrin-G, and generates action potentials. As the role of spiking in AIIs is uncertain, we hypothesized that the morphological properties of the AIS-like process could provide information relevant for its functional importance, including potential pre- and/or postsynaptic connectivity. For morphological analysis, we injected AII amacrine cells in slices with fluorescent dye and immunolabeled the slices for ankyrin-G. Subsequently, this enabled us to reliably identify AII-type processes among ankyrin-G-labeled processes in wholemount retina. We systematically analyzed the laminar localization, spatial orientation, and distribution of the AIS-like processes as a function of retinal eccentricity. In the horizontal plane, the processes displayed no preferred orientation and terminal endings were randomly distributed. In the vertical plane, the processes displayed a horizontal preference, but also ascended and descended into the inner nuclear layer and proximal inner plexiform layer, respectively. These results suggest that the AII amacrine AIS-like process is unlikely to take part in conventional synaptic connections, but may instead be adapted to respond to volume neurotransmission by means of extrasynaptic receptors.
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Affiliation(s)
- Jian Hao Liu
- Department of Biomedicine, University of Bergen, Bergen, Norway
| | | | | | - Espen Hartveit
- Department of Biomedicine, University of Bergen, Bergen, Norway
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11
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Oesterle J, Behrens C, Schröder C, Hermann T, Euler T, Franke K, Smith RG, Zeck G, Berens P. Bayesian inference for biophysical neuron models enables stimulus optimization for retinal neuroprosthetics. eLife 2020; 9:e54997. [PMID: 33107821 PMCID: PMC7673784 DOI: 10.7554/elife.54997] [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: 01/08/2020] [Accepted: 10/26/2020] [Indexed: 01/02/2023] Open
Abstract
While multicompartment models have long been used to study the biophysics of neurons, it is still challenging to infer the parameters of such models from data including uncertainty estimates. Here, we performed Bayesian inference for the parameters of detailed neuron models of a photoreceptor and an OFF- and an ON-cone bipolar cell from the mouse retina based on two-photon imaging data. We obtained multivariate posterior distributions specifying plausible parameter ranges consistent with the data and allowing to identify parameters poorly constrained by the data. To demonstrate the potential of such mechanistic data-driven neuron models, we created a simulation environment for external electrical stimulation of the retina and optimized stimulus waveforms to target OFF- and ON-cone bipolar cells, a current major problem of retinal neuroprosthetics.
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Affiliation(s)
- Jonathan Oesterle
- Institute for Ophthalmic Research, University of TübingenTübingenGermany
| | - Christian Behrens
- Institute for Ophthalmic Research, University of TübingenTübingenGermany
| | - Cornelius Schröder
- Institute for Ophthalmic Research, University of TübingenTübingenGermany
| | - Thoralf Hermann
- Naturwissenschaftliches und Medizinisches Institut an der Universität TübingenReutlingenGermany
| | - Thomas Euler
- Institute for Ophthalmic Research, University of TübingenTübingenGermany
- Center for Integrative Neuroscience, University of TübingenTübingenGermany
- Bernstein Center for Computational Neuroscience, University of TübingenTübingenGermany
| | - Katrin Franke
- Institute for Ophthalmic Research, University of TübingenTübingenGermany
- Bernstein Center for Computational Neuroscience, University of TübingenTübingenGermany
| | - Robert G Smith
- Department of Neuroscience, University of PennsylvaniaPhiladelphiaUnited States
| | - Günther Zeck
- Naturwissenschaftliches und Medizinisches Institut an der Universität TübingenReutlingenGermany
| | - Philipp Berens
- Institute for Ophthalmic Research, University of TübingenTübingenGermany
- Center for Integrative Neuroscience, University of TübingenTübingenGermany
- Bernstein Center for Computational Neuroscience, University of TübingenTübingenGermany
- Institute for Bioinformatics and Medical Informatics, University of TübingenTübingenGermany
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12
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Kawai F, Ohkuma M, Horiguchi M, Ichinose H, Miyachi EI. A subset of cone bipolar cells expresses the Na + channel SCN2A in the human retina. Exp Eye Res 2020; 202:108299. [PMID: 33068627 DOI: 10.1016/j.exer.2020.108299] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2020] [Revised: 10/08/2020] [Accepted: 10/09/2020] [Indexed: 11/24/2022]
Abstract
Some bipolar cells in the human retina are known to express voltage-gated Na+ channels. However, it is unclear which types of channels are expressed, and whether Na+ channel expression is limited to specific types of bipolar cells. In the present study, we examined the types of voltage-gated Na+ channels expressed in human bipolar cells and the morphology of bipolar cells with voltage-gated Na+ currents. To investigate the expression of voltage-gated Na+ channels in human bipolar cells, we examined whether Na+ channel transcripts could be detected in single bipolar cells using the reverse transcription polymerase chain reaction (RT-PCR) technique. The voltage-gated Na+ current was recorded from isolated bipolar cells using the patch-clamp recording technique. Types of bipolar cells that have the Na+ currents were investigated by analyzing their morphology after staining with Lucifer yellow. Using RT-PCR, the SCN2A Na+ channel was detected in 5 of 6 isolated bipolar cells. This suggests that a subset of human bipolar cells expresses the SCN2A Na+ channel. Under voltage-clamp conditions, depolarizing voltage steps induced a fast transient inward current in cone bipolar cells with axon terminal boutons that stratified at the ON layer, which includes the stratum 3, 4, and 5 of the inner plexiform layer (IPL, n = 2/11 cells). The fast transient inward current of isolated bipolar cells was blocked by 1 μM of tetrodotoxin (TTX), a voltage-gated Na+ channel blocker. No fast transient inward current was recorded with axon terminals that stratify at the OFF layer, which includes stratum 1 and 2 of the IPL (n = 4). Thus, a subset of ON cone bipolar cells at least expresses the putative voltage-gated Na+ channel SCN2A in the human retina. The Na+ channels in the bipolar cells may serve to amplify the release of neurotransmitter, glutamate, when membrane potential is rapidly depolarized and thereby selectively accelerating light responses.
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Affiliation(s)
- Fusao Kawai
- Deptartment of Physiology, School of Medicine, Fujita Health University, Japan.
| | - Mahito Ohkuma
- Deptartment of Physiology, School of Medicine, Fujita Health University, Japan
| | - Masayuki Horiguchi
- Deptartment of Ophthalmology, School of Medicine, Fujita Health University, Japan
| | - Hiroshi Ichinose
- Institute for Comprehensive Medical Science, Fujita Health University, Japan; Present address:School of Life Science and Technology, Tokyo Institute of Technology, Japan
| | - Ei-Ichi Miyachi
- Deptartment of Physiology, School of Medicine, Fujita Health University, Japan
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13
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Hellmer CB, Bohl JM, Hall LM, Koehler CC, Ichinose T. Dopaminergic Modulation of Signal Processing in a Subset of Retinal Bipolar Cells. Front Cell Neurosci 2020; 14:253. [PMID: 32922266 PMCID: PMC7456991 DOI: 10.3389/fncel.2020.00253] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2020] [Accepted: 07/23/2020] [Indexed: 11/13/2022] Open
Abstract
The retina and the olfactory bulb are the gateways to the visual and olfactory systems, respectively, similarly using neural networks to initiate sensory signal processing. Sensory receptors receive signals that are transmitted to neural networks before projecting to primary cortices. These networks filter sensory signals based on their unique features and adjust their sensitivities by gain control systems. Interestingly, dopamine modulates sensory signal transduction in both systems. In the retina, dopamine adjusts the retinal network for daylight conditions (“light adaptation”). In the olfactory system, dopamine mediates lateral inhibition between the glomeruli, resulting in odorant signal decorrelation and discrimination. While dopamine is essential for signal discrimination in the olfactory system, it is not understood whether dopamine has similar roles in visual signal processing in the retina. To elucidate dopaminergic effects on visual processing, we conducted patch-clamp recording from second-order retinal bipolar cells, which exhibit multiple types that can convey different temporal features of light. We recorded excitatory postsynaptic potentials (EPSPs) evoked by various frequencies of sinusoidal light in the absence and presence of a dopamine receptor 1 (D1R) agonist or antagonist. Application of a D1R agonist, SKF-38393, shifted the peak temporal responses toward higher frequencies in a subset of bipolar cells. In contrast, a D1R antagonist, SCH-23390, reversed the effects of SKF on these types of bipolar cells. To examine the mechanism of dopaminergic modulation, we recorded voltage-gated currents, hyperpolarization-activated cyclic nucleotide-gated (HCN) channels, and low-voltage activated (LVA) Ca2+ channels. SKF modulated HCN and LVA currents, suggesting that these channels are the target of D1R signaling to modulate visual signaling in these bipolar cells. Taken together, we found that dopamine modulates the temporal tuning of a subset of retinal bipolar cells. Consequently, we determined that dopamine plays a role in visual signal processing, which is similar to its role in signal decorrelation in the olfactory bulb.
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Affiliation(s)
- Chase B Hellmer
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, Detroit, MI, United States
| | - Jeremy M Bohl
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, Detroit, MI, United States
| | - Leo M Hall
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, Detroit, MI, United States
| | - Christina C Koehler
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, Detroit, MI, United States
| | - Tomomi Ichinose
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, Detroit, MI, United States
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14
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Grünert U, Martin PR. Cell types and cell circuits in human and non-human primate retina. Prog Retin Eye Res 2020; 78:100844. [PMID: 32032773 DOI: 10.1016/j.preteyeres.2020.100844] [Citation(s) in RCA: 76] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2019] [Revised: 01/28/2020] [Accepted: 01/31/2020] [Indexed: 12/12/2022]
Abstract
This review summarizes our current knowledge of primate including human retina focusing on bipolar, amacrine and ganglion cells and their connectivity. We have two main motivations in writing. Firstly, recent progress in non-invasive imaging methods to study retinal diseases mean that better understanding of the primate retina is becoming an important goal both for basic and for clinical sciences. Secondly, genetically modified mice are increasingly used as animal models for human retinal diseases. Thus, it is important to understand to which extent the retinas of primates and rodents are comparable. We first compare cell populations in primate and rodent retinas, with emphasis on how the fovea (despite its small size) dominates the neural landscape of primate retina. We next summarise what is known, and what is not known, about the postreceptoral neurone populations in primate retina. The inventories of bipolar and ganglion cells in primates are now nearing completion, comprising ~12 types of bipolar cell and at least 17 types of ganglion cell. Primate ganglion cells show clear differences in dendritic field size across the retina, and their morphology differs clearly from that of mouse retinal ganglion cells. Compared to bipolar and ganglion cells, amacrine cells show even higher morphological diversity: they could comprise over 40 types. Many amacrine types appear conserved between primates and mice, but functions of only a few types are understood in any primate or non-primate retina. Amacrine cells appear as the final frontier for retinal research in monkeys and mice alike.
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Affiliation(s)
- Ulrike Grünert
- The University of Sydney, Save Sight Institute, Faculty of Medicine and Health, Sydney, NSW, 2000, Australia; Australian Research Council Centre of Excellence for Integrative Brain Function, Sydney Node, The University of Sydney, Sydney, NSW, 2000, Australia.
| | - Paul R Martin
- The University of Sydney, Save Sight Institute, Faculty of Medicine and Health, Sydney, NSW, 2000, Australia; Australian Research Council Centre of Excellence for Integrative Brain Function, Sydney Node, The University of Sydney, Sydney, NSW, 2000, Australia
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15
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Popova E, Kupenova P. Effects of HCN channel blockade on the intensity-response function of electroretinographic ON and OFF responses in dark adapted frogs. Acta Neurobiol Exp (Wars) 2020. [DOI: 10.21307/ane-2020-018] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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16
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Spatiotemporally Asymmetric Excitation Supports Mammalian Retinal Motion Sensitivity. Curr Biol 2019; 29:3277-3288.e5. [PMID: 31564498 PMCID: PMC6865067 DOI: 10.1016/j.cub.2019.08.048] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2019] [Revised: 08/15/2019] [Accepted: 08/20/2019] [Indexed: 11/20/2022]
Abstract
The detection of visual motion is a fundamental function of the visual system. How motion speed and direction are computed together at the cellular level, however, remains largely unknown. Here, we suggest a circuit mechanism by which excitatory inputs to direction-selective ganglion cells in the mouse retina become sensitive to the motion speed and direction of image motion. Electrophysiological, imaging, and connectomic analyses provide evidence that the dendrites of ON direction-selective cells receive spatially offset and asymmetrically filtered glutamatergic inputs along motion-preference axis from asymmetrically wired bipolar and amacrine cell types with distinct release dynamics. A computational model shows that, with this spatiotemporal structure, the input amplitude becomes sensitive to speed and direction by a preferred direction enhancement mechanism. Our results highlight the role of an excitatory mechanism in retinal motion computation by which feature selectivity emerges from non-selective inputs.
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17
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Hall LM, Hellmer CB, Koehler CC, Ichinose T. Bipolar Cell Type-Specific Expression and Conductance of Alpha-7 Nicotinic Acetylcholine Receptors in the Mouse Retina. Invest Ophthalmol Vis Sci 2019; 60:1353-1361. [PMID: 30934054 PMCID: PMC6738513 DOI: 10.1167/iovs.18-25753] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Purpose Motion detection is performed by a unique neural network in the mouse retina. Starburst amacrine cells (SACs), which release acetylcholine and gamma-aminobutyric acid (GABA) into the network, are key neurons in the motion detection pathway. Although GABA contributions to the network have been extensively studied, the role of acetylcholine is minimally understood. Acetylcholine receptors are present in a subset of bipolar, amacrine, and ganglion cells. We focused on α7-nicotinic acetylcholine receptor (α7-nAChR) expression in bipolar cells, and investigated which types of bipolar cells possess α7-nAChRs. Methods Retinal slice sections were prepared from C57BL/6J and Gus8.4-GFP mice. Specific expression of α7-nAChRs in bipolar cells was examined using α-bungarotoxin (αBgTx)-conjugated Alexa dyes co-labeled with specific bipolar cell markers. Whole-cell recordings were conducted from bipolar cells in retinal slice sections. A selective α7-nAChR agonist, PNU282987, was applied by a puff and responses were recorded. Results αBgTx fluorescence was observed primarily in bipolar cell somas. We found that α7-nAChRs were expressed by the majority of type 1, 2, 4, and 7 bipolar cells. Whole-cell recordings revealed that type 2 and 7 bipolar cells depolarized by PNU application. In contrast, α7-nAChRs were not detected in most of type 3, 5, 6, and rod bipolar cells. Conclusions We found that α7-nAChRs are present in bipolar cells in a type-specific manner. Because these bipolar cells provide synaptic inputs to SACs and direction selective ganglion cells, α7-nAChRs may play a role in direction selectivity by modulating these bipolar cells' outputs.
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Affiliation(s)
- Leo M Hall
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, Detroit, Michigan, United States
| | - Chase B Hellmer
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, Detroit, Michigan, United States
| | - Christina C Koehler
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, Detroit, Michigan, United States
| | - Tomomi Ichinose
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, Detroit, Michigan, United States
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18
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Van Hook MJ, Nawy S, Thoreson WB. Voltage- and calcium-gated ion channels of neurons in the vertebrate retina. Prog Retin Eye Res 2019; 72:100760. [PMID: 31078724 PMCID: PMC6739185 DOI: 10.1016/j.preteyeres.2019.05.001] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2019] [Revised: 04/25/2019] [Accepted: 05/01/2019] [Indexed: 02/06/2023]
Abstract
In this review, we summarize studies investigating the types and distribution of voltage- and calcium-gated ion channels in the different classes of retinal neurons: rods, cones, horizontal cells, bipolar cells, amacrine cells, interplexiform cells, and ganglion cells. We discuss differences among cell subtypes within these major cell classes, as well as differences among species, and consider how different ion channels shape the responses of different neurons. For example, even though second-order bipolar and horizontal cells do not typically generate fast sodium-dependent action potentials, many of these cells nevertheless possess fast sodium currents that can enhance their kinetic response capabilities. Ca2+ channel activity can also shape response kinetics as well as regulating synaptic release. The L-type Ca2+ channel subtype, CaV1.4, expressed in photoreceptor cells exhibits specific properties matching the particular needs of these cells such as limited inactivation which allows sustained channel activity and maintained synaptic release in darkness. The particular properties of K+ and Cl- channels in different retinal neurons shape resting membrane potentials, response kinetics and spiking behavior. A remaining challenge is to characterize the specific distributions of ion channels in the more than 100 individual cell types that have been identified in the retina and to describe how these particular ion channels sculpt neuronal responses to assist in the processing of visual information by the retina.
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Affiliation(s)
- Matthew J Van Hook
- Truhlsen Eye Institute, Department of Ophthalmology & Visual Sciences, University of Nebraska Medical Center, Omaha, NE, USA
| | - Scott Nawy
- Truhlsen Eye Institute, Department of Ophthalmology & Visual Sciences, University of Nebraska Medical Center, Omaha, NE, USA; Department Pharmacology & Experimental Neuroscience(2), University of Nebraska Medical Center, Omaha, NE, USA
| | - Wallace B Thoreson
- Truhlsen Eye Institute, Department of Ophthalmology & Visual Sciences, University of Nebraska Medical Center, Omaha, NE, USA; Department Pharmacology & Experimental Neuroscience(2), University of Nebraska Medical Center, Omaha, NE, USA.
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19
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Tetenborg S, Yadav SC, Brüggen B, Zoidl GR, Hormuzdi SG, Monyer H, van Woerden GM, Janssen-Bienhold U, Dedek K. Localization of Retinal Ca 2+/Calmodulin-Dependent Kinase II-β (CaMKII-β) at Bipolar Cell Gap Junctions and Cross-Reactivity of a Monoclonal Anti-CaMKII-β Antibody With Connexin36. Front Mol Neurosci 2019; 12:206. [PMID: 31555090 PMCID: PMC6724749 DOI: 10.3389/fnmol.2019.00206] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2019] [Accepted: 08/07/2019] [Indexed: 11/13/2022] Open
Abstract
Neuronal gap junctions formed by connexin36 (Cx36) and chemical synapses share striking similarities in terms of plasticity. Ca2+/calmodulin-dependent protein kinase II (CaMKII), an enzyme known to induce memory formation at chemical synapses, has recently been described to potentiate electrical coupling in the retina and several other brain areas via phosphorylation of Cx36. The contribution of individual CaMKII isoforms to this process, however, remains unknown. We recently identified CaMKII-β at electrical synapses in the mouse retina. Now, we set out to identify cell types containing Cx36 gap junctions that also express CaMKII-β. To ensure precise description, we first tested the specificity of two commercially available antibodies on CaMKII-β-deficient retinas. We found that a polyclonal antibody was highly specific for CaMKII-β. However, a monoclonal antibody (CB-β-1) recognized CaMKII-β but also cross-reacted with the C-terminal tail of Cx36, making localization analyses with this antibody inaccurate. Using the polyclonal antibody, we identified strong CaMKII-β expression in bipolar cell terminals that were secretagogin- and HCN1-positive and thus represent terminals of type 5 bipolar cells. In these terminals, a small fraction of CaMKII-β also colocalized with Cx36. A similar pattern was observed in putative type 6 bipolar cells although there, CaMKII expression seemed less pronounced. Next, we tested whether CaMKII-β influenced the Cx36 expression in bipolar cell terminals by quantifying the number and size of Cx36-immunoreactive puncta in CaMKII-β-deficient retinas. However, we found no significant differences between the genotypes, indicating that CaMKII-β is not necessary for the formation and maintenance of Cx36-containing gap junctions in the retina. In addition, in wild-type retinas, we observed frequent association of Cx36 and CaMKII-β with synaptic ribbons, i.e., chemical synapses, in bipolar cell terminals. This arrangement resembled the composition of mixed synapses found for example in Mauthner cells, in which electrical coupling is regulated by glutamatergic activity. Taken together, our data imply that CaMKII-β may fulfill several functions in bipolar cell terminals, regulating both Cx36-containing gap junctions and ribbon synapses and potentially also mediating cross-talk between these two types of bipolar cell outputs.
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Affiliation(s)
- Stephan Tetenborg
- Animal Navigation/Neurosensorics, Institute for Biology and Environmental Sciences, University of Oldenburg, Oldenburg, Germany
| | - Shubhash Chandra Yadav
- Animal Navigation/Neurosensorics, Institute for Biology and Environmental Sciences, University of Oldenburg, Oldenburg, Germany
| | - Bianca Brüggen
- Animal Navigation/Neurosensorics, Institute for Biology and Environmental Sciences, University of Oldenburg, Oldenburg, Germany
| | - Georg R Zoidl
- Department of Biology & Center for Vision Research, York University, Toronto, ON, Canada
| | - Sheriar G Hormuzdi
- Division of Neuroscience, Ninewells Hospital and Medical School, University of Dundee, Dundee, United Kingdom
| | | | - Geeske M van Woerden
- Department of Neuroscience, Erasmus MC University Medical Center, Rotterdam, Netherlands
| | - Ulrike Janssen-Bienhold
- Department of Neuroscience, Visual Neuroscience, University of Oldenburg, Oldenburg, Germany.,Research Center Neurosensory Science, University of Oldenburg, Oldenburg, Germany
| | - Karin Dedek
- Animal Navigation/Neurosensorics, Institute for Biology and Environmental Sciences, University of Oldenburg, Oldenburg, Germany.,Research Center Neurosensory Science, University of Oldenburg, Oldenburg, Germany
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20
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Vlasits AL, Euler T, Franke K. Function first: classifying cell types and circuits of the retina. Curr Opin Neurobiol 2019; 56:8-15. [DOI: 10.1016/j.conb.2018.10.011] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2018] [Accepted: 10/24/2018] [Indexed: 12/30/2022]
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21
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Rattay F, Bassereh H, Stiennon I. Compartment models for the electrical stimulation of retinal bipolar cells. PLoS One 2018; 13:e0209123. [PMID: 30557410 PMCID: PMC6296559 DOI: 10.1371/journal.pone.0209123] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2018] [Accepted: 11/29/2018] [Indexed: 11/30/2022] Open
Abstract
Bipolar cells of the retina are among the smallest neurons of the nervous system. For this reason, compared to other neurons, their delay in signaling is minimal. Additionally, the small bipolar cell surface combined with the low membrane conductance causes very little attenuation in the signal from synaptic input to the terminal. The existence of spiking bipolar cells was proven over the last two decades, but until now no complete model including all important ion channel types was published. The present study amends this and analyzes the impact of the number of model compartments on simulation accuracy. Characteristic features like membrane voltages and spike generation were tested and compared for one-, two-, four- and 117-compartment models of a macaque bipolar cell. Although results were independent of the compartment number for low membrane conductances (passive membranes), nonlinear regimes such as spiking required at least a separate axon compartment. At least a four compartment model containing the functionally different segments dendrite, soma, axon and terminal was needed for understanding signaling in spiking bipolar cells. Whereas for intracellular current application models with small numbers of compartments showed quantitatively correct results in many cases, the cell response to extracellular stimulation is sensitive to spatial variation of the electric field and accurate modeling therefore demands for a large number of short compartments even for passive membranes.
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Affiliation(s)
- Frank Rattay
- Institute for Analysis and Scientific Computing, Vienna University of Technology, Wiedner Hauptstrasse, Vienna, Austria
- * E-mail:
| | - Hassan Bassereh
- Institute for Analysis and Scientific Computing, Vienna University of Technology, Wiedner Hauptstrasse, Vienna, Austria
| | - Isabel Stiennon
- Institute for Analysis and Scientific Computing, Vienna University of Technology, Wiedner Hauptstrasse, Vienna, Austria
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22
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Abstract
Retinal first-order neurons, photoreceptors, receive visual inputs and convert them to neural signals. The second-order neurons, bipolar cells then sort out the visual signals and encode them through multiple neural streams. Approximately 15 morphological types of bipolar cells have been identified, which are thought to encode different aspects of visual signals such as motion and color (Ichinose et al. J Neurosci 34(26):8761-8771, 2014; Euler et al. Nat Rev Neurosci 15(8):507-519, 2014). To investigate functional aspects of OFF bipolar cells, single cell recordings are preferred; however, bipolar cells in the mouse retina are small and hard to distinguish from other types of cells. Here, we describe our methodology and tips for immunohistochemistry and patch clamp recordings for analyzing light-evoked responses in each type of OFF bipolar cell.
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Affiliation(s)
- Chase B Hellmer
- Departments of Anatomy and Cell Biology, Wayne State University School of Medicine, Detroit, MI, USA
| | - Tomomi Ichinose
- Departments of Anatomy and Cell Biology, Wayne State University School of Medicine, Detroit, MI, USA.
- Department of Ophthalmology, Wayne State University School of Medicine, Detroit, MI, USA.
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23
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Agurto A, Vielma AH, Cadiz B, Couve E, Schmachtenberg O. NO signaling in retinal bipolar cells. Exp Eye Res 2017; 161:30-35. [PMID: 28579034 DOI: 10.1016/j.exer.2017.05.013] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2016] [Revised: 04/28/2017] [Accepted: 05/30/2017] [Indexed: 01/22/2023]
Abstract
Nitric oxide (NO) is a neuromodulator involved in physiological and pathological processes in the retina. In the inner retina, a subgroup of amacrine cells have been shown to synthesize NO, but bipolar cells remain controversial as NO sources. This study correlates NO synthesis in dark-adapted retinas, through labeling with the NO marker DAF-FM, with neuronal nitric oxide synthase (nNOS) and inducible NOS expression, and presence of the NO receptor soluble guanylate cyclase in bipolar cells. NO containing bipolar cells were morphologically identified by dialysis of DAF fluorescent cells with intracellular dyes, or by DAF labeling followed by immunohistochemistry for nNOS and other cellular markers. DAF fluorescence was observed in all types of bipolar cells that could be identified, but the most intense DAF fluorescence was observed in bipolar cells with severed processes, supporting pathological NO signaling. Among nNOS expressing bipolar cells, type 9 was confirmed unequivocally, while types 2, 3a, 3b, 4, 5, 7, 8 and the rod bipolar cell were devoid of this enzyme. These results establish specific bipolar cell types as NO sources in the inner retina, and support the involvement of NO signaling in physiological and pathological processes in the inner retina.
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Affiliation(s)
- A Agurto
- Centro Interdisciplinario de Neurociencia de Valparaíso (CINV), Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile
| | - A H Vielma
- Centro Interdisciplinario de Neurociencia de Valparaíso (CINV), Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile
| | - B Cadiz
- Centro Interdisciplinario de Neurociencia de Valparaíso (CINV), Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile; Instituto de Biología, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile
| | - E Couve
- Instituto de Biología, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile
| | - O Schmachtenberg
- Centro Interdisciplinario de Neurociencia de Valparaíso (CINV), Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile.
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24
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Shekhar K, Lapan SW, Whitney IE, Tran NM, Macosko EZ, Kowalczyk M, Adiconis X, Levin JZ, Nemesh J, Goldman M, McCarroll SA, Cepko CL, Regev A, Sanes JR. Comprehensive Classification of Retinal Bipolar Neurons by Single-Cell Transcriptomics. Cell 2016; 166:1308-1323.e30. [PMID: 27565351 DOI: 10.1016/j.cell.2016.07.054] [Citation(s) in RCA: 702] [Impact Index Per Article: 87.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2016] [Revised: 06/10/2016] [Accepted: 07/28/2016] [Indexed: 12/15/2022]
Abstract
Patterns of gene expression can be used to characterize and classify neuronal types. It is challenging, however, to generate taxonomies that fulfill the essential criteria of being comprehensive, harmonizing with conventional classification schemes, and lacking superfluous subdivisions of genuine types. To address these challenges, we used massively parallel single-cell RNA profiling and optimized computational methods on a heterogeneous class of neurons, mouse retinal bipolar cells (BCs). From a population of ∼25,000 BCs, we derived a molecular classification that identified 15 types, including all types observed previously and two novel types, one of which has a non-canonical morphology and position. We validated the classification scheme and identified dozens of novel markers using methods that match molecular expression to cell morphology. This work provides a systematic methodology for achieving comprehensive molecular classification of neurons, identifies novel neuronal types, and uncovers transcriptional differences that distinguish types within a class.
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Affiliation(s)
- Karthik Shekhar
- Broad Institute of Harvard and MIT, Cambridge, MA 02142, USA
| | - Sylvain W Lapan
- Department of Genetics, Harvard Medical School, Boston, MA 02115, USA; Howard Hughes Medical Institute, Chevy Chase, MD 20815, USA
| | - Irene E Whitney
- Center for Brain Science and Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA 02130, USA
| | - Nicholas M Tran
- Center for Brain Science and Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA 02130, USA
| | - Evan Z Macosko
- Department of Genetics, Harvard Medical School, Boston, MA 02115, USA; Stanley Center for Psychiatric Research, Broad Institute of Harvard and MIT, Cambridge, MA 02142, USA; Program in Medical and Population Genetics, Broad Institute of Harvard and MIT, Cambridge, MA 02142, USA
| | | | - Xian Adiconis
- Broad Institute of Harvard and MIT, Cambridge, MA 02142, USA; Stanley Center for Psychiatric Research, Broad Institute of Harvard and MIT, Cambridge, MA 02142, USA
| | - Joshua Z Levin
- Broad Institute of Harvard and MIT, Cambridge, MA 02142, USA; Stanley Center for Psychiatric Research, Broad Institute of Harvard and MIT, Cambridge, MA 02142, USA
| | - James Nemesh
- Department of Genetics, Harvard Medical School, Boston, MA 02115, USA; Stanley Center for Psychiatric Research, Broad Institute of Harvard and MIT, Cambridge, MA 02142, USA; Program in Medical and Population Genetics, Broad Institute of Harvard and MIT, Cambridge, MA 02142, USA
| | - Melissa Goldman
- Department of Genetics, Harvard Medical School, Boston, MA 02115, USA; Stanley Center for Psychiatric Research, Broad Institute of Harvard and MIT, Cambridge, MA 02142, USA
| | - Steven A McCarroll
- Department of Genetics, Harvard Medical School, Boston, MA 02115, USA; Stanley Center for Psychiatric Research, Broad Institute of Harvard and MIT, Cambridge, MA 02142, USA; Program in Medical and Population Genetics, Broad Institute of Harvard and MIT, Cambridge, MA 02142, USA
| | - Constance L Cepko
- Department of Genetics, Harvard Medical School, Boston, MA 02115, USA; Department of Ophthalmology, Harvard Medical School, Boston, MA 02115, USA; Howard Hughes Medical Institute, Chevy Chase, MD 20815, USA.
| | - Aviv Regev
- Broad Institute of Harvard and MIT, Cambridge, MA 02142, USA; Howard Hughes Medical Institute, Chevy Chase, MD 20815, USA; Department of Biology and Koch Institute, MIT, Cambridge, MA 02139, USA.
| | - Joshua R Sanes
- Center for Brain Science and Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA 02130, USA.
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