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Hanson L, Sethuramanujam S, deRosenroll G, Jain V, Awatramani GB. Retinal direction selectivity in the absence of asymmetric starburst amacrine cell responses. eLife 2019; 8:42392. [PMID: 30714905 PMCID: PMC6377229 DOI: 10.7554/elife.42392] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2018] [Accepted: 02/01/2019] [Indexed: 01/18/2023] Open
Abstract
In the mammalian retina, direction-selectivity is thought to originate in the dendrites of GABAergic/cholinergic starburst amacrine cells, where it is first observed. However, here we demonstrate that direction selectivity in downstream ganglion cells remains remarkably unaffected when starburst dendrites are rendered non-directional, using a novel strategy combining a conditional GABAA α2 receptor knockout mouse with optogenetics. We show that temporal asymmetries between excitation/inhibition, arising from the differential connectivity patterns of starburst cholinergic and GABAergic synapses to ganglion cells, form the basis for a parallel mechanism generating direction selectivity. We further demonstrate that these distinct mechanisms work in a coordinated way to refine direction selectivity as the stimulus crosses the ganglion cell’s receptive field. Thus, precise spatiotemporal patterns of inhibition and excitation that determine directional responses in ganglion cells are shaped by two ‘core’ mechanisms, both arising from distinct specializations of the starburst network.
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Affiliation(s)
- Laura Hanson
- Department of Biology, University of Victoria, Victoria, Canada
| | | | | | - Varsha Jain
- Department of Biology, University of Victoria, Victoria, Canada
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Neural architecture of the "transient" ON directionally selective (class IIb1) ganglion cells in rabbit retina, partly co-stratified with starburst amacrine cells. Vis Neurosci 2017; 33:E004. [PMID: 27484854 DOI: 10.1017/s0952523815000358] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Recent physiological studies coupled with intracellular staining have subdivided ON directionally selective (DS) ganglion cells of rabbit retina into two types. One exhibits more "transient" and more "brisk" responses (ON DS-t), and the other has more "sustained' and more "sluggish" responses (ON DS-s), although both represent the same three preferred directions and show preference for low stimulus velocity, as reported in previous studies of ON DS ganglion cells in rabbit retina. ON DS-s cells have the morphology of ganglion cells previously shown to project to the medial terminal nucleus (MTN) of the accessory optic system, and the MTN-projecting, class IVus1 cells have been well-characterized previously in terms of their dendritic morphology, branching pattern, and stratification. ON DS-t ganglion cells have a distinctly different morphology and exhibit heterotypic coupling to amacrine cells, including axon-bearing amacrine cells, with accompanying synchronous firing, while ON DS-s cells are not coupled. The present study shows that ON DS-t cells are morphologically identical to the previously well-characterized, "orphan" class IIb1 ganglion cell, previously regarded as a member of the "brisk-concentric" category of ganglion cells. Its branching pattern, quantitatively analyzed, is similar to that of the morphological counterparts of X and Y cells, and very different from that of the ON DS-s ganglion cell. Close analysis of the dendritic stratification of class IIb1 ganglion cells together with fiducial cells indicates that they differ from that of the ON DS-s cells. In agreement with one of the three previous studies, class IIb1/ON DS-t cells, unlike class IVus1/ON DS-s ganglion cells, in the main do not co-stratify with starburst amacrine cells. As the present study shows, however, portions of their dendrites do deviate from the main substratum, coming within range of starburst boutons. Parsimony favors DS input from starburst amacrine cells both to ON DS-s and to ON DS-t ganglion cells, given the similarity of their DS responses, but further studies will be required to substantiate the origin of the DS responses of ON DS-t cells. Previously reported OFF DS responses in ON DS-t cells, unmasked by pharmacological agents, and mediated by gap junctions with amacrine cells, suggests an unusual trans-sublaminar organization of directional selectivity in the inner plexiform layer, connecting sublamina a and sublamina b.
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Lee JS, Kim HG, Jeon CJ. Identification of synaptic pattern of NMDA receptor subunits upon direction-selective retinal ganglion cells in developing and adult mouse retina. Acta Histochem 2017; 119:495-507. [PMID: 28545760 DOI: 10.1016/j.acthis.2017.05.002] [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: 08/21/2016] [Revised: 04/30/2017] [Accepted: 05/05/2017] [Indexed: 11/25/2022]
Abstract
Direction selectivity of the retina is a unique mechanism and critical function of eyes for surviving. Direction-selective retinal ganglion cells (DS RGCs) strongly respond to preferred directional stimuli, but rarely respond to the opposite or null directional stimuli. These DS RGCs are sensitive to glutamate, which is secreted from bipolar cells. Using immunocytochemistry, we studied with the distributions of N-methyl-d-aspartate (NMDA) receptor subunits on the dendrites of DS RGCs in the developing and adult mouse retina. DS RGCs were injected with Lucifer yellow for identification of dendritic morphology. The triple-labeled images of dendrites, kinesin II, and NMDA receptor subunits were visualized using confocal microscopy and were reconstructed from high-resolution confocal images. Although our results revealed that the synaptic pattern of NMDA receptor subunits on dendrites of DS RGCs was not asymmetric in developing and adult mouse retina, they showed the anatomical connectivity of NMDA glutamatergic synapses onto DS RGCs and the developmental formation of the direction selectivity in the mouse retina. Through the comprehensive interpretation of the direction-selective neural circuit, this study, therefore, implies that the direction selectivity may be generated by the asymmetry of the excitatory glutamatergic inputs and the inhibitory inputs onto DS RGCs.
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Norton DJ, McBain RK, Pizzagalli DA, Cronin-Golomb A, Chen Y. Dysregulation of visual motion inhibition in major depression. Psychiatry Res 2016; 240:214-221. [PMID: 27111216 PMCID: PMC4886228 DOI: 10.1016/j.psychres.2016.04.028] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/16/2015] [Revised: 03/22/2016] [Accepted: 04/13/2016] [Indexed: 11/19/2022]
Abstract
Individuals with depression show depleted concentrations of the inhibitory neurotransmitter GABA in occipital (visual) cortex, predicting weakened inhibition within their visual systems. Yet, visual inhibition in depression remains largely unexplored. To fill this gap, we examined the inhibitory process of center-surround suppression (CSS) of visual motion in depressed individuals. Perceptual performance in discriminating the direction of motion was measured as a function of stimulus presentation time and contrast in depressed individuals (n=27) and controls (n=22). CSS was operationalized as the accuracy difference between conditions using large (7.5°) and small (1.5°) grating stimuli. Both depressed and control participants displayed the expected advantage in accuracy for small stimuli at high contrast. A significant interaction emerged between subject group, contrast level and presentation time, indicating that alterations of CSS in depression were modulated by stimulus conditions. At high contrast, depressed individuals showed significantly greater CSS than controls at the 66ms presentation time (where the effect peaked in both groups). The results' specificity and dependence on stimulus features such as contrast, size and presentation time suggest that they arise from changes in early visual processing, and are not the results of a generalized deficit or cognitive bias.
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Affiliation(s)
- Daniel J Norton
- Department of Psychological and Brain Sciences, Boston University, Boston, MA, USA; McLean Hospital, and Department of Psychiatry, Harvard Medical School, Belmont, MA, USA; Massachusetts General Hospital, Boston MA, USA.
| | - Ryan K McBain
- Department of Global Health and Population, Harvard School of Public Health, Boston, MA, USA
| | - Diego A Pizzagalli
- McLean Hospital, and Department of Psychiatry, Harvard Medical School, Belmont, MA, USA
| | - Alice Cronin-Golomb
- Department of Psychological and Brain Sciences, Boston University, Boston, MA, USA
| | - Yue Chen
- McLean Hospital, and Department of Psychiatry, Harvard Medical School, Belmont, MA, USA
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Kwon OJ, Lee JS, Kim HG, Jeon CJ. Identification of Synaptic Patterns of NMDA Receptor Subtypes Upon Direction-Selective Rabbit Retinal Ganglion Cells. Curr Eye Res 2015; 41:832-43. [PMID: 26287656 DOI: 10.3109/02713683.2015.1056378] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
PURPOSE The objective of this study was to identify anisotropies that contribute to the directional preference of direction-selective retinal ganglion cells (DS RGCs) in the rabbit retina. We investigated the distributions of N-methyl-d-aspartate receptor 1 (NMDAR1), NMDAR2A and NMDAR2B receptor subunits in the dendritic arbors of rabbit DS RGCs. METHODS The distributions of the NMDAR subunits on the DS RGCs were determined using immunocytochemistry. DS RGCs were injected with Lucifer yellow, and the cells were identified by their characteristic morphology. The triple-labeled images of dendrites, kinesin II and NMDARs were visualized using confocal microscopy and were reconstructed from high-resolution confocal images. RESULTS We found no evidence of asymmetry in any of the NMDAR subunits examined on the dendritic arbors of both the ON and OFF layers of DS RGCs. CONCLUSIONS Our results indicate that direction selectivity appears to lie in the neuronal circuitry afferent to the DS RGCs.
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Affiliation(s)
- Oh-Ju Kwon
- a Department of Optometry , Busan Institute of Science and Technology , Busan , South Korea and.,b Department of Biology , School of Life Sciences, BK21 Plus KNU Creative BioResearch Group, College of Natural Sciences, and Brain Science and Engineering Institute, Kyungpook National University , Daegu , South Korea
| | - Jun-Seok Lee
- b Department of Biology , School of Life Sciences, BK21 Plus KNU Creative BioResearch Group, College of Natural Sciences, and Brain Science and Engineering Institute, Kyungpook National University , Daegu , South Korea
| | - Hang-Gu Kim
- b Department of Biology , School of Life Sciences, BK21 Plus KNU Creative BioResearch Group, College of Natural Sciences, and Brain Science and Engineering Institute, Kyungpook National University , Daegu , South Korea
| | - Chang-Jin Jeon
- b Department of Biology , School of Life Sciences, BK21 Plus KNU Creative BioResearch Group, College of Natural Sciences, and Brain Science and Engineering Institute, Kyungpook National University , Daegu , South Korea
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Popova E. GABAergic neurotransmission and retinal ganglion cell function. J Comp Physiol A Neuroethol Sens Neural Behav Physiol 2015; 201:261-83. [PMID: 25656810 DOI: 10.1007/s00359-015-0981-z] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2014] [Revised: 01/19/2015] [Accepted: 01/21/2015] [Indexed: 01/13/2023]
Abstract
Ganglion cells are the output retinal neurons that convey visual information to the brain. There are ~20 different types of ganglion cells, each encoding a specific aspect of the visual scene as spatial and temporal contrast, orientation, direction of movement, presence of looming stimuli; etc. Ganglion cell functioning depends on the intrinsic properties of ganglion cell's membrane as well as on the excitatory and inhibitory inputs that these cells receive from other retinal neurons. GABA is one of the most abundant inhibitory neurotransmitters in the retina. How it modulates the activity of different types of ganglion cells and what is its significance in extracting the basic features from visual scene are questions with fundamental importance in visual neuroscience. The present review summarizes current data concerning the types of membrane receptors that mediate GABA action in proximal retina; the effects of GABA and its antagonists on the ganglion cell light-evoked postsynaptic potentials and spike discharges; the action of GABAergic agents on centre-surround organization of the receptive fields and feature related ganglion cell activity. Special emphasis is put on the GABA action regarding the ON-OFF and sustained-transient ganglion cell dichotomy in both nonmammalian and mammalian retina.
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Affiliation(s)
- E Popova
- Department of Physiology, Medical Faculty, Medical University, 1431, Sofia, Bulgaria,
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Kim HJ, Jeon CJ. Synaptic pattern of nicotinic acetylcholine receptor α7 and β2 subunits on the direction-selective retinal ganglion cells in the postnatal mouse retina. Exp Eye Res 2014; 122:54-64. [PMID: 24631336 DOI: 10.1016/j.exer.2014.02.021] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2013] [Revised: 02/18/2014] [Accepted: 02/25/2014] [Indexed: 11/26/2022]
Abstract
Direction-selective retinal ganglion cells (DS RGCs) respond strongly to a stimulus that moves in their preferred direction, but respond weakly or do not respond to a stimulus that moves in the opposite or null direction. DS RGCs are sensitive to acetylcholine, and starburst amacrine cells (SACs) make cholinergic synapses on DS RGCs. We studied the distributions of nicotinic acetylcholine receptor (nAChR) α7 and β2 subunits on the dendritic arbors of DS RGCs to search for anisotropies that contribute to the directional preferences of DS RGCs. The DS RGCs from the retinas of postnatal mice (postnatal day P5, P10, and P15) were injected with Lucifer yellow, and injected cells were identified by their dendritic morphology. The dendrites of the DS RGCs were labeled with antibodies for either the nAChR α7 or β2 subunit as well as postsynaptic density protein-95 (PSD-95), visualized by confocal microscopy, and reconstructed from high-resolution confocal images. The distribution of nAChR subunits on the dendritic arbors in both the ON and OFF layers of the RGCs revealed an asymmetrical pattern on early postnatal day P5. However, the distributions of nAChR subunits on the dendritic arbors were not asymmetric on P10 and P15. Our results therefore provide anatomical and developmental evidence suggesting that the nAChR α7 and β2 subunits may involve in the early direction-selectivity formation of DS RGCs in the mouse retina.
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Affiliation(s)
- Hyun Jin Kim
- Department of Biology, School of Life Sciences, KNU Creative BioResearch Group (BK21 Plus Program), College of Natural Sciences, and Brain Science and Engineering Institute, Kyungpook National University, Daegu 702-701, South Korea; Department of Life Sciences, Pohang University of Science and Technology, Pohang, Kyungpook 790-784, South Korea
| | - Chang Jin Jeon
- Department of Biology, School of Life Sciences, KNU Creative BioResearch Group (BK21 Plus Program), College of Natural Sciences, and Brain Science and Engineering Institute, Kyungpook National University, Daegu 702-701, South Korea.
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8
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Abstract
The review deals with the morphology, physiology, topography, and central projections of direction-selective cells of the accessory optic system in vertebrates.
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Affiliation(s)
- Igor I Pushchin
- Laboratory of Physiology, A. V. Zhirmunsky Institute of Marine Biology, Far Eastern Branch, Russian Academy of Sciences, Vladivostok 690059, Russia
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Rivlin-Etzion M, Wei W, Feller MB. Visual stimulation reverses the directional preference of direction-selective retinal ganglion cells. Neuron 2013; 76:518-25. [PMID: 23141064 DOI: 10.1016/j.neuron.2012.08.041] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2012] [Accepted: 08/31/2012] [Indexed: 11/16/2022]
Abstract
Direction selectivity in the retina is mediated by direction-selective ganglion cells. These cells are part of a circuit in which they are asymmetrically wired to inhibitory neurons. Thus, they respond strongly to an image moving in the preferred direction and weakly to an image moving in the opposite (null) direction. Here, we demonstrate that adaptation with short visual stimulation of a direction-selective ganglion cell using drifting gratings can reverse this cell's directional preference by 180°. This reversal is robust, long lasting, and independent of the animal's age. Our findings indicate that, even within circuits that are hardwired, the computation of direction can be altered by dynamic circuit mechanisms that are guided by visual stimulation.
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Affiliation(s)
- Michal Rivlin-Etzion
- Department of Molecular and Cell Biology and the Helen Wills Neurosciences Institute, UC Berkeley, Berkeley, CA 94720, USA
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Lee JG, Lee KP, Jeon CJ. Synaptic Pattern of KA1 and KA2 upon the Direction-Selective Ganglion Cells in Developing and Adult Mouse Retina. Acta Histochem Cytochem 2012; 45:35-45. [PMID: 22489103 PMCID: PMC3317494 DOI: 10.1267/ahc.11043] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2011] [Accepted: 12/01/2011] [Indexed: 11/22/2022] Open
Abstract
The detection of image motion is important to vision. Direction-selective retinal ganglion cells (DS-RGCs) respond strongly to stimuli moving in one direction of motion and are strongly inhibited by stimuli moving in the opposite direction. In this article, we investigated the distributions of kainate glutamate receptor subtypes KA1 and KA2 on the dendritic arbors of DS-RGCs in developing (5, 10) days postnatal (PN) and adult mouse retina to search for anisotropies. The distribution of kainate receptor subtypes on the DS-RGCs was determined using antibody immunocytochemistry. To identify their characteristic morphology, DS-RGCs were injected with Lucifer yellow. The triple-labeled images of dendrites, kinesin II, and receptors were visualized by confocal microscopy and were reconstructed from high-resolution confocal images. We found no evidence of asymmetry in any of the kainate receptor subunits examined on the dendritic arbors of both the On and Off layers of DS-RGCs in all periods of developing and adult stage that would predict direction selectivity.
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Affiliation(s)
- Jee-Geon Lee
- Department of Biology, College of Natural Sciences, and Brain Science and Engineering Institute, Kyungpook National University
| | - Kyoung-Pil Lee
- Department of Biology, College of Natural Sciences, and Brain Science and Engineering Institute, Kyungpook National University
| | - Chang-Jin Jeon
- Department of Biology, College of Natural Sciences, and Brain Science and Engineering Institute, Kyungpook National University
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11
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Trenholm S, Johnson K, Li X, Smith RG, Awatramani GB. Parallel mechanisms encode direction in the retina. Neuron 2011; 71:683-94. [PMID: 21867884 PMCID: PMC3269126 DOI: 10.1016/j.neuron.2011.06.020] [Citation(s) in RCA: 108] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/03/2011] [Indexed: 11/24/2022]
Abstract
In the retina, presynaptic inhibitory mechanisms that shape directionally selective (DS) responses in output ganglion cells are well established. However, the nature of inhibition-independent forms of directional selectivity remains poorly defined. Here, we describe a genetically specified set of ON-OFF DS ganglion cells (DSGCs) that code anterior motion. This entire population of DSGCs exhibits asymmetric dendritic arborizations that orientate toward the preferred direction. We demonstrate that morphological asymmetries along with nonlinear dendritic conductances generate a centrifugal (soma-to-dendrite) preference that does not critically depend upon, but works in parallel with the GABAergic circuitry. We also show that in symmetrical DSGCs, such dendritic DS mechanisms are aligned with, or are in opposition to, the inhibitory DS circuitry in distinct dendritic subfields where they differentially interact to promote or weaken directional preferences. Thus, pre- and postsynaptic DS mechanisms interact uniquely in distinct ganglion cell populations, enabling efficient DS coding under diverse conditions.
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Affiliation(s)
- Stuart Trenholm
- Department of Anatomy and Neurobiology, Dalhousie University, 5850 College Street, Halifax, NS B3H 1X5, Canada
| | - Kyle Johnson
- Department of Anatomy and Neurobiology, Dalhousie University, 5850 College Street, Halifax, NS B3H 1X5, Canada
| | - Xiao Li
- Department of Neuroscience, University of Pennsylvania, 123 Anatomy-Chemistry Building/6058, 422 Curie Boulevard, Philadelphia, PA 19104, USA
| | - Robert G. Smith
- Department of Neuroscience, University of Pennsylvania, 123 Anatomy-Chemistry Building/6058, 422 Curie Boulevard, Philadelphia, PA 19104, USA
| | - Gautam B. Awatramani
- Department of Anatomy and Neurobiology, Dalhousie University, 5850 College Street, Halifax, NS B3H 1X5, Canada
- Ophthalmology and Visual Sciences, Dalhousie University, 5850 College Street, Halifax, NS B3H 1X5, Canada
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12
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Wiring specificity in the direction-selectivity circuit of the retina. Nature 2011; 471:183-8. [PMID: 21390125 DOI: 10.1038/nature09818] [Citation(s) in RCA: 576] [Impact Index Per Article: 44.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2010] [Accepted: 01/10/2011] [Indexed: 02/01/2023]
Abstract
The proper connectivity between neurons is essential for the implementation of the algorithms used in neural computations, such as the detection of directed motion by the retina. The analysis of neuronal connectivity is possible with electron microscopy, but technological limitations have impeded the acquisition of high-resolution data on a large enough scale. Here we show, using serial block-face electron microscopy and two-photon calcium imaging, that the dendrites of mouse starburst amacrine cells make highly specific synapses with direction-selective ganglion cells depending on the ganglion cell's preferred direction. Our findings indicate that a structural (wiring) asymmetry contributes to the computation of direction selectivity. The nature of this asymmetry supports some models of direction selectivity and rules out others. It also puts constraints on the developmental mechanisms behind the formation of synaptic connections. Our study demonstrates how otherwise intractable neurobiological questions can be addressed by combining functional imaging with the analysis of neuronal connectivity using large-scale electron microscopy.
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Nowak P, Dobbins AC, Gawne TJ, Grzywacz NM, Amthor FR. Separability of stimulus parameter encoding by on-off directionally selective rabbit retinal ganglion cells. J Neurophysiol 2011; 105:2083-99. [PMID: 21325684 DOI: 10.1152/jn.00941.2010] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The ganglion cell output of the retina constitutes a bottleneck in sensory processing in that ganglion cells must encode multiple stimulus parameters in their responses. Here we investigate encoding strategies of On-Off directionally selective retinal ganglion cells (On-Off DS RGCs) in rabbits, a class of cells dedicated to representing motion. The exquisite axial discrimination of these cells to preferred vs. null direction motion is well documented: it is invariant with respect to speed, contrast, spatial configuration, spatial frequency, and motion extent. However, these cells have broad direction tuning curves and their responses also vary as a function of other parameters such as speed and contrast. In this study, we examined whether the variation in responses across multiple stimulus parameters is systematic, that is the same for all cells, and separable, such that the response to a stimulus is a product of the effects of each stimulus parameter alone. We extracellularly recorded single On-Off DS RGCs in a superfused eyecup preparation while stimulating them with moving bars. We found that spike count responses of these cells scaled as independent functions of direction, speed, and luminance. Moreover, the speed and luminance functions were common across the whole sample of cells. Based on these findings, we developed a model that accurately predicted responses of On-Off DS RGCs as products of separable functions of direction, speed, and luminance (r = 0.98; P < 0.0001). Such a multiplicatively separable encoding strategy may simplify the decoding of these cells' outputs by the higher visual centers.
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Affiliation(s)
- Przemyslaw Nowak
- Department of Vision Sciences, University of Alabama at Birmingham, Birmingham, AL 35294-1170, USA
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14
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POZNANSKI RR. CELLULAR INHIBITORY BEHAVIOR UNDERLYING THE FORMATION OF RETINAL DIRECTION SELECTIVITY IN THE STARBURST NETWORK. J Integr Neurosci 2010; 9:299-335. [DOI: 10.1142/s0219635210002457] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2010] [Accepted: 08/26/2010] [Indexed: 11/18/2022] Open
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15
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Ackert JM, Farajian R, Völgyi B, Bloomfield SA. GABA blockade unmasks an OFF response in ON direction selective ganglion cells in the mammalian retina. J Physiol 2009; 587:4481-95. [PMID: 19651763 PMCID: PMC2766652 DOI: 10.1113/jphysiol.2009.173344] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2009] [Accepted: 07/27/2009] [Indexed: 11/08/2022] Open
Abstract
One unique subtype of retinal ganglion cell is the direction selective (DS) cell, which responds vigorously to stimulus movement in a preferred direction, but weakly to movement in the opposite or null direction. Here we show that the application of the GABA receptor blocker picrotoxin unmasks a robust excitatory OFF response in ON DS ganglion cells. Similar to the characteristic ON response of ON DS cells, the masked OFF response is also direction selective, but its preferred direction is opposite to that of the ON component. Given that the OFF response is unmasked with picrotoxin, its direction selectivity cannot be generated by a GABAergic mechanism. Alternatively, we find that the direction selectivity of the OFF response is blocked by cholinergic drugs, suggesting that acetylcholine release from presynaptic starburst amacrine cells is crucial for its generation. Finally, we find that the OFF response is abolished by application of a gap junction blocker, suggesting that it arises from electrical synapses between ON DS and polyaxonal amacrine cells. Our results suggest a novel role for gap junctions in mixing excitatory ON and OFF signals at the ganglion cell level. We propose that OFF inputs to ON DS cells are normally masked by a GABAergic inhibition, but are unmasked under certain stimulus conditions to mediate optokinetic signals in the brain.
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Affiliation(s)
- Jessica M Ackert
- Department of Physiology & Neuroscience, New York University School of Medicine, 550 First Avenue, New York, NY 10016, USA
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16
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Mora-Ferrer C, Neumeyer C. Neuropharmacology of vision in goldfish: A review. Vision Res 2009; 49:960-9. [DOI: 10.1016/j.visres.2008.08.004] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2007] [Revised: 07/16/2008] [Accepted: 08/11/2008] [Indexed: 11/27/2022]
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17
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Renna JM, Strang CE, Amthor FR, Keyser KT. Strychnine, but not PMBA, inhibits neuronal nicotinic acetylcholine receptors expressed by rabbit retinal ganglion cells. Vis Neurosci 2007; 24:503-11. [PMID: 17900376 DOI: 10.1017/s0952523807070241] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2006] [Accepted: 03/02/2007] [Indexed: 02/07/2023]
Abstract
Strychnine is considered a selective competitive antagonist of glycine gated Cl- channels (Saitoh et al., 1994) and studies have used strychnine at low micromolar concentrations to study the role of glycine in rabbit retina (Linn, 1998; Protti et al., 2005). However, other studies have shown that strychnine, in the concentrations commonly used, is also a potent competitive antagonist of alpha7 nicotinic acetylcholine receptors (nAChRs; Matsubayashi et al., 1998). We tested the effects of low micromolar concentrations of strychnine and 3-[2'-phosphonomethyl[1,1'-biphenyl]-3-yl] alanine (PMBA), a specific glycine receptor blocker (Saitoh et al., 1994; Hosie et al., 1999) on the activation of both alpha7 nAChRs on retinal ganglion cells and on ganglion cell responses to a light flash. Extracellular recordings were obtained from ganglion cells in an isolated retina/choroid preparation and 500 microM choline was used as an alpha7 agonist (Alkondon et al., 1997). We recorded from brisk sustained and brisk transient OFF cells, many of which have been previously shown to have alpha7 receptors (Strang et al., 2005). Further, we tested the effect of strychnine, PMBA and alpha-bungarotoxin on the binding of tetramethylrhodamine alpha-bungarotoxin in the inner plexiform layer. Our data indicates that strychnine, at doses as low as 1.0 microM, can inhibit the alpha7 nAChR-mediated response to choline, but PMBA at concentrations as high as 0.4 microM does not. Binding studies show strychnine and alpha-bungarotoxin inhibit binding of labeled alpha-bungarotoxin in the IPL. Thus, the effects of strychnine application may be to inhibit glycine receptors expressed by ganglion cell or to inhibit amacrine cell alpha7 nAChRs, both of which would result in an increase in the ganglion cell responses. Further research will be required to disentangle the effects of strychnine previously believed to be caused by a single mechanism of glycine receptor inhibition.
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Affiliation(s)
- J M Renna
- Department of Vision Sciences, University Alabama-Birmingham, Birmingham, Alabama 35294, USA
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Grzywacz NM, Amthor FR. Robust directional computation in on-off directionally selective ganglion cells of rabbit retina. Vis Neurosci 2007; 24:647-61. [PMID: 17900380 DOI: 10.1017/s0952523807070666] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2007] [Accepted: 08/17/2007] [Indexed: 11/06/2022]
Abstract
The spatial and temporal interactions in the receptive fields of On-Off directionally selective (DS) ganglion cells endow them with directional selectivity. Using a variety of stimuli, such as sinusoidal gratings, we show that these interactions make directional selectivity of the DS ganglion cell robust with respect to stimulus parameters such as contrast, speed, spatial frequency, and extent of motion. Moreover, unlike the directional selectivity of striate-cortex cells, On-Off DS ganglion cells display directional selectivity to motions not oriented perpendicularly to the contour of the objects. We argue that these cells may achieve such high robustness by combining multiple mechanisms of directional selectivity.
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Affiliation(s)
- Norberto M Grzywacz
- Department of Biomedical Engineering and Neuroscience Graduate Program, University of Southern California, Los Angeles, California, USA
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19
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Strang CE, Renna JM, Amthor FR, Keyser KT. Nicotinic acetylcholine receptor expression by directionally selective ganglion cells. Vis Neurosci 2007; 24:523-33. [PMID: 17686198 DOI: 10.1017/s0952523807070435] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2006] [Accepted: 04/25/2007] [Indexed: 11/06/2022]
Abstract
Acetylcholine (ACh) enhances the preferred direction responses of directionally selective ganglion cells (DS GCs; Ariel & Daw, 1982; Ariel & Adolph, 1985) through the activation of nicotinic acetylcholine receptors (nAChRs; Ariel & Daw, 1982; Massey et al., 1997; Kittila & Massey, 1997). DS GCs appear to express at least two types of nAChRs, those that are sensitive to the partially subtype-specific antagonist methyllycaconitine (MLA), and those that are MLA-insensitive (Reed et al., 2002). Our purpose was to confirm the expression of alpha7 nAChRs by DS GCs and to assess the contributions of other nAChR subtypes to DS GC responses. Using choline as a nAChR partially subtype-specific agonist, we found that the majority of DS GCs demonstrated responses to choline while under synaptic blockade. The blockade or reduction of choline-induced responses by bath application of nanomolar (nM) concentrations of MLA provided direct evidence that the choline responses were mediated by alpha7 nAChRs. Because choline is a partial agonist for alpha3beta4 nAChRs (Alkondon et al., 1997), the residual choline responses are consistent with mediation by alpha3beta4 nAChRs. Additionally, a subset of DS GCs responded to nicotine but not to choline, indicating the expression of a third nAChR subtype. The pharmacological results were supported by single cell reverse transcription polymerase chain reaction (RT-PCR) and immunohistochemistry experiments. The expression of alpha7 and specific non-alpha7 nAChR subtypes was correlated with the preferred direction. This indicates the possibility of differential responses to ACh depending on the direction of movement. This is the first description of differential expression of multiple nAChR subtypes by DS GCs.
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Affiliation(s)
- Christianne E Strang
- Department of Vision Sciences, University of Alabama at Birmingham, Birmingham, Alabama 35294, USA.
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20
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Lee EJ, Merwine DK, Padilla M, Grzywacz NM. Choline acetyltransferase-immunoreactive neurons in the retina of normal and dark-reared turtle. J Comp Neurol 2007; 503:768-78. [PMID: 17570494 DOI: 10.1002/cne.21416] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Visual deprivation alters retinal-ganglion-cell response properties through changes in spontaneous wave-like activity (Sernagor and Grzywacz [1996] Curr Biol 6:1503-1508). This activity depends on cholinergic synaptic transmission in the turtle retina (ibid; Sernagor and Mehta [ 2001] J Anat 199:375-383). We studied the expression of choline acetyltransferase (ChAT) by immunocytochemistry and Western blot in developing retinas of control and dark-reared turtles. At postnatal day 0 (P0), right after hatching, ChAT-immunoreactivity was present in the ganglion cell layer (GCL), in the inner nuclear layer (INL), and in two distinct bands of the inner plexiform layer (IPL). In P14- and P28-control, and P14- and P28-dark-reared retinas, ChAT-immunoreactivity showed similar patterns to those in P0. However, in P14- and P28-dark-reared retinas the density of ChAT-immunoreactive cells was higher in both the INL and GCL than in P14- and P28-control retinas, respectively. Moreover, Western blotting showed that ChAT protein levels were significantly increased in the dark-reared retina compared to those of the control. TUNEL studies indicated that the difference between normal and dark-reared conditions was not due to extra apoptosis in the former. In turn, proliferating-cell nuclear antigen immunocytochemistry showed no extra proliferating cells in the latter. Finally, nearest-neighbor analysis revealed that the denser population of cholinergic cells in dark-reared turtles formed a mosaic as regular as the normal ones in the GCL. Thus, light deprivation increases the expression of ChAT, increasing the apparent density of cholinergic neurons in the developing turtle retina.
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Affiliation(s)
- Eun-Jin Lee
- Department of Biomedical Engineering, Neuroscience Graduate Program, and Center for Vision Science and Technology, University of Southern California, Los Angeles, California 90089-1111, USA
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21
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Grzywacz NM, Zucker CL. Modeling Starburst cells' GABA(B) receptors and their putative role in motion sensitivity. Biophys J 2006; 91:473-86. [PMID: 16648160 PMCID: PMC1483088 DOI: 10.1529/biophysj.105.072256] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2005] [Accepted: 04/10/2006] [Indexed: 11/18/2022] Open
Abstract
Neal and Cunningham (Neal, M. J., and J. R. Cunningham. 1995. J. Physiol. (Lond.). 482:363-372) showed that GABA(B) agonists and glycinergic antagonists enhance the light-evoked release of retinal acetylcholine. They proposed that glycinergic cells inhibit the cholinergic Starburst amacrine cells and are in turn inhibited by GABA through GABA(B) receptors. However, as recently shown, glycinergic cells do not appear to have GABA(B) receptors. In contrast, the Starburst amacrine cell has GABA(B) receptors in a subpopulation of its varicosities. We thus propose an alternate model in which GABA(B)-receptor activation reduces the release of ACh from some dendritic compartments onto a glycinergic cell, which then feeds back and inhibits the Starburst cell. In this model, the GABA necessary to make these receptors active comes from the Starburst cell itself, making them autoreceptors. Computer simulations of this model show that it accounts quantitatively for the Neal and Cunningham data. We also argue that GABA(B) receptors could work to increase the sensitivity to motion over other stimuli.
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Affiliation(s)
- Norberto M Grzywacz
- Department of Biomedical Engineering, Neuroscience Graduate Program, and Center For Visual Science and Technology, University of Southern California, Los Angeles, California, USA.
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22
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Amthor FR, Tootle JS, Grzywacz NM. Stimulus-dependent correlated firing in directionally selective retinal ganglion cells. Vis Neurosci 2006; 22:769-87. [PMID: 16469187 DOI: 10.1017/s0952523805226081] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2005] [Accepted: 07/15/2005] [Indexed: 11/06/2022]
Abstract
Synchronous spiking has been postulated to be a meta-signal in visual cortex and other CNS loci that tags neuronal spike responses to a single entity. In retina, however, synchronized spikes have been postulated to arise via mechanisms that would largely preclude their carrying such a code. One such mechanism is gap junction coupling, in which synchronous spikes would be a by-product of lateral signal sharing. Synchronous spikes have also been postulated to arise from common-source inputs to retinal ganglion cells having overlapping receptive fields, and thus code for stimulus location in the overlap area. On-Off directionally selective ganglion cells of the rabbit retina exhibit a highly precise tiling pattern in which gap junction coupling occurs between some neighboring, same-preferred-direction cells. Depending on how correlated spikes arise, and for what purpose, one could postulate that synchronized spikes in this system (1) always arise in some subset of same-direction cells because of gap junctions, but never in non-same-preferred-directional cells; (2) never arise in same-directional cells because their receptive fields do not overlap, but arise only in different-directional cells whose receptive fields overlap, as a code for location in the overlap region; or (3) arise in a stimulus-dependent manner for both same- and different-preferred-direction cells for a function similar to that postulated for neurons in visual cortex. Simultaneous, extracellular recordings were obtained from neighboring On-Off directionally selective (DS) ganglion cells having the same and different preferred directions in an isolated rabbit retinal preparation. Stimulation by large flashing spots elicited responses from DS ganglion-cell pairs that typically showed little synchronous firing. Movement of extended bars, however, often produced synchronous spikes in cells having similar or orthogonal preferred directions. Surprisingly, correlated firing could occur for the opposite contrast polarity edges of moving stimuli when the leading edge of a sweeping bar excited the receptive field of one cell as its trailing edge stimulated another. Pharmacological manipulations showed that the spike synchronization is enhanced by excitatory cholinergic amacrine-cell inputs, and reduced by inhibitory GABAergic inputs, in a motion-specific manner. One possible interpretation is that this synchronous firing could be a signal to higher centers that the outputs of the two DS ganglion cells should be "bound" together as responding to a contour of a common object.
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Affiliation(s)
- Franklin R Amthor
- Department of Psychology, University of Alabama at Birmingham, 35294-1170, USA.
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23
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Amthor FR, Tootle JS, Gawne TJ. Retinal ganglion cell coding in simulated active vision. Vis Neurosci 2006; 22:789-806. [PMID: 16469188 DOI: 10.1017/s0952523805226093] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2005] [Accepted: 07/15/2005] [Indexed: 11/08/2022]
Abstract
The image on the retina is almost never static. Eye, head, and body
movements, and externally generated motion create rapid and continual
changes in the retinal image (“active vision”). Virtually all
vision in animals such as primates, which make saccades as often as
3–4 times/s, is based on information that must be derived from
the first few hundred milliseconds after sudden, global changes in the
retinal image. These changes may be accompanied by large changes in area
mean luminance, as well as higher order image contrast statistics. This
study investigated how retinal ganglion cell responses, whose response
properties have been typically studied and defined in a stable stimulus
regime, are affected by sudden changes in mean luminance that are
characteristic of active vision. Specifically, the steady-state responses
of retinal ganglion cells to static or moving square-wave grating stimuli
were recorded in an isolated, superfused rabbit eyecup preparation and
compared to responses after saccade-like changes in luminance. The manner
of coding after luminance changes was different for different ganglion
cell classes; both suppression and enhancement of responses to patterns
following luminance changes were found. Brisk-transient Off cells
unambiguously signaled the darkening of the overall image, but were also
modulated by the subsequently appearing grating stimulus. Several types of
On-center cell behavior were observed, ranging from strong suppression of
the subsequent response by luminance changes, to strong enhancement.
Overall, most ganglion cells distinguished static patterns after a
luminance change via differences in their spike discharges nearly
as well as before, although there were clear asymmetries between the On
and Off pathways. Changes in mean luminance in some ganglion cells, such
as On–Off directionally selective ganglion cells, could create large
phase shifts in the response to patterned, moving stimuli, although these
stimuli were still detected immediately after luminance changes. The
results of this study show that the image dynamics of active vision may be
a fundamental challenge for the visual system because of strong effects on
retinal ganglion cell function. However, rapid extraction of unambiguous
information after luminance changes appears to be encoded in differences
in the spike discharges in different retinal ganglion cell classes.
Asymmetries among ganglion cell classes in sensitivity to luminance
changes may provide a basis by which some provide the
“context” for interpreting the firing of others.
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Affiliation(s)
- Franklin R Amthor
- Department of Psychology, University of Alabama at Birmingham, 35294-1170, USA.
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24
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Zucker CL, Nilson JE, Ehinger B, Grzywacz NM. Compartmental localization of gamma-aminobutyric acid type B receptors in the cholinergic circuitry of the rabbit retina. J Comp Neurol 2005; 493:448-59. [PMID: 16261535 PMCID: PMC2849668 DOI: 10.1002/cne.20766] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Although many effects of gamma-aminobutyric acid (GABA) on retinal function have been attributed to GABA(A) and GABA(C) receptors, specific retinal functions have also been shown to be mediated by GABA(B) receptors, including facilitation of light-evoked acetylcholine release from the rabbit retina (Neal and Cunningham [1995] J. Physiol. 482:363-372). To explain the results of a rich set of experiments, Neal and Cunningham proposed a model for this facilitation. In this model, GABA(B) receptor-mediated inhibition of glycinergic cells would reduce their own inhibition of cholinergic cells. In turn, muscarinic input from the latter to the glycinergic cells would complete a negative-feedback circuitry. In this study, we have used immunohistochemical techniques to test elements of this model. We report that glycinergic amacrine cells are GABA(B) receptor negative. In contrast, our data reveal the localization of GABA(B) receptors on cholinergic/GABAergic starburst amacrine cells. High-resolution localization of GABA(B) receptors on starburst amacrine cells shows that they are discretely localized to a limited population of its varicosities, the majority of likely synaptic-release sites being devoid of detectable levels of GABA(B) receptors. Finally, we identify a glycinergic cell that is a potential muscarinic receptor-bearing target of GABA(B)-modulated acetylcholine release. This target is the DAPI-3 cell. We propose, based on these data, a modification of the Neal and Cunningham model in which GABA(B) receptors are on starburst, not glycinergic amacrine cells.
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Affiliation(s)
- Charles L Zucker
- Department Anatomy and Neurobiology, Boston University School of Medicine, 715 Albany Street, Massachusetts 02118, USA.
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25
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Mora-Ferrer C, Hausselt S, Schmidt Hoffmann R, Ebisch B, Schick S, Wollenberg K, Schneider C, Teege P, Jürgens K. Pharmacological properties of motion vision in goldfish measured with the optomotor response. Brain Res 2005; 1058:17-29. [PMID: 16150425 DOI: 10.1016/j.brainres.2005.07.073] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2005] [Revised: 07/21/2005] [Accepted: 07/22/2005] [Indexed: 11/26/2022]
Abstract
In goldfish, the retinal pathways involved in motion coding have been demonstrated to have an L-cone dominated action spectrum (S. Schaerer, C. Neumeyer, Motion detection in goldfish investigated with the optomotor response is "color blind", Vision Res. 36 (1996) 4025-4034). The neurotransmitters involved in retinal motion coding mechanisms, and the relevance of these retinal motion coding mechanisms for motion perception, are little investigated in fish. In this study, the optomotor response was used to investigate the effect of antagonists on different receptor types for acetylcholine (ACh), GABA, for the dopamine D2-receptor (D2-R) - which is known to modulate the action spectrum in motion coding (C. Mora-Ferrer, K. Behrend, Dopaminergic modulation of photopic temporal transfer properties in goldfish retina investigated with the ERG, Vision Res. 44 (2004) 2067-2081) - and of an agonist for against the mGluR6-receptor (mGluR6) on goldfish motion vision in the photopic range. Blockade of nicotinic ACh-R, GABAa-R and both GABAa- and GABAc-R eliminated the optomotor response completely. Neither a muscarinic ACH-R antagonist, a D2-R antagonist or a mGluR6-agonist affected goldfish motion vision. The pharmacological profile of the goldfish optomotor response resembles the pharmacological profile of direction-selective ganglion cells (DS-GC) described for vertebrate retinas in electrophysiological experiments, e.g. (S. Weng, W. Sun, S. He, Identification of ON-OFF direction-selective ganglion cells in the mouse retina, J. Physiol. 562 (2005) 915-923). This indicates that cells with direction-selective receptive field properties exist in the goldfish retina. It is proposed that these cells provide the input for the full field motion perception in goldfish.
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MESH Headings
- Acetylcholine/metabolism
- Animals
- Dopamine/metabolism
- Eye Movements/drug effects
- Eye Movements/physiology
- GABA Antagonists/pharmacology
- Goldfish
- Motion Perception/drug effects
- Motion Perception/physiology
- Nicotinic Antagonists/pharmacology
- Psychomotor Performance/drug effects
- Psychomotor Performance/physiology
- Receptors, Dopamine D2/drug effects
- Receptors, Dopamine D2/metabolism
- Receptors, GABA/drug effects
- Receptors, GABA/metabolism
- Receptors, GABA-A/drug effects
- Receptors, GABA-A/metabolism
- Receptors, Nicotinic/drug effects
- Receptors, Nicotinic/metabolism
- Retina/cytology
- Retina/drug effects
- Retina/physiology
- Retinal Ganglion Cells/cytology
- Retinal Ganglion Cells/drug effects
- Retinal Ganglion Cells/physiology
- Vision, Ocular/drug effects
- Vision, Ocular/physiology
- Visual Fields/physiology
- gamma-Aminobutyric Acid/metabolism
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Affiliation(s)
- Carlos Mora-Ferrer
- Institute Zoology III, J Gutenberg University Mainz, 55099 Mainz, Germany.
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26
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Poznanski RR. BIOPHYSICAL MECHANISMS AND ESSENTIAL TOPOGRAPHY OF DIRECTIONALLY SELECTIVE SUBUNITS IN RABBIT'S RETINA. J Integr Neurosci 2005; 4:341-61. [PMID: 16178062 DOI: 10.1142/s0219635205000860] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2005] [Accepted: 06/16/2005] [Indexed: 11/18/2022] Open
Abstract
We commemorate the 40th anniversary of the classical study undertaken by Barlow-Levick with a new challenge: to show how direction selectivity in the dendritic plexus of starburst amacrine cells is being computed. In the rabbit retina, although the cellular locus of direction selectivity is known to occur predominantly in the dendrites of starburst amacrine cells, the biophysical mechanism by which this takes place and its essential topography are yet to be specified with precision. A cotransmission model, involving a conjoint release of excitation/inhibition (i.e., a bisynaptic relay of endogenous ACh and GABA) from the distal varicosities of individual starburst amacrines, will be non-diphasic when the vesicular release of Ach and the non-vesicular, carrier-mediated release of GABA by transporters in the anterograde direction are preferentially suppressed by a negative feedback mechanism involving autoreceptors. Such biophysical mechanisms, including the asymmetric distribution of chloride cotransporters, explain somatofugal motion bias in starburst amacrine cells leading to autonomous functioning "subunits" that underlie the formation of directional selectivity. However, the functional independence of starburst amacrine cell "subunits" is partly a question of their network organization. The topography of directionally selective "subunits" resides in the plexus of crisscrossing dendrites of juxtaposed starburst amacrines, consisting of (i) serial synapses of three or more starburst amacrines and a ON-OFF directionally selective ganglion cell; (ii) a synaptic couplet between two starburst amacrines; and (iii) a conventional synapse between a starburst amacrine and a ON-OFF directionally selective ganglion cell. Cholinergic and GABAergic monosynaptic interactions between starburst amacrine cells, including glutamatergic interactions with cone bipolar cells, are involved in the primary circuit underlying directional selectivity. Furthermore, the secondary circuit underlying directional selectivity, consists of starburst amacrine cells and cone bipolar cells arranged in a "push-pull" configuration, interacting synaptically onto ON-OFF directionally selective ganglion cells.
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Affiliation(s)
- Roman R Poznanski
- Claremont Research Institute of Applied Mathematical Sciences, Claremont Graduate University, Claremont, CA 91711-3988, USA.
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27
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Strang CE, Andison ME, Amthor FR, Keyser KT. Rabbit retinal ganglion cells express functional alpha7 nicotinic acetylcholine receptors. Am J Physiol Cell Physiol 2005; 289:C644-55. [PMID: 15872006 DOI: 10.1152/ajpcell.00633.2004] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
It is well known that cholinergic agents affect ganglion cell (GC) firing rates and light responses in the retinas of many species, but the specific receptor subtypes involved in mediating these effects have been only partially characterized. We sought to determine whether functional alpha(7) nicotinic acetylcholine receptors (nAChRs) contribute to the responses of specific retinal GC classes in rabbit retina. We used electrophysiology, pharmacology, immunohistochemistry, and reverse transcriptase-polymerase chain reaction to determine the pharmacological properties and expression of nAChR subtypes by specific rabbit retinal GC classes. Choline was used as an alpha(7) nAChR agonist. Methyllycaconitine (MLA) was used as a competitive alpha(7) nAChR antagonist. The application of choline before synaptic blockade resulted in changes in retinal GC activity, including increases or decreases in maintained firing and/or enhancement or suppression of light responses. Many physiologically identified GC types, including sustained off, sustained on, transient off, and transient on cells, demonstrated responses to choline application while under synaptic blockade. The choline-induced responses could be blocked with MLA, confirming alpha(7) nAChR activation. Individual choline-responsive GCs displayed mRNA transcripts consistent with the expression of functional alpha(7) nAChRs. Other GCs demonstrated physiological responses and mRNA expression consistent with the expression of both alpha(7) and non-alpha(7) nAChRs. Thus mRNA is present for multiple nAChR subunits in whole retina extracts, and functional alpha(7) nAChRs are capable of modulating the responses of GCs in adult rabbit retina. We also demonstrate through physiological responses that subsets of GCs express more than one nAChR subtype.
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Affiliation(s)
- Christianne E Strang
- Department of Vision Science, University of Alabama, Birmingham, AL 35294-4390, USA
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28
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Reed BT, Keyser KT, Amthor FR. MLA-sensitive cholinergic receptors involved in the detection of
complex moving stimuli in retina. Vis Neurosci 2005; 21:861-72. [PMID: 15733341 DOI: 10.1017/s0952523804216066] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2003] [Indexed: 11/07/2022]
Abstract
Acetylcholine, acting through nicotinic acetylcholine receptors,
mediates the response properties of many ganglion cells in the rabbit
retina, including those that are directionally selective (DS; Ariel
& Daw, 1982a,b). For example, Grzywacz et al. (1998) showed that cholinergic input is necessary
for DS responses to drifting gratings, a form of textured stimulus.
However, the identities and locations of the neuronal acetylcholine
receptor (nAChR) subtypes that mediate this input are not clear (Keyser et al., 2000). We investigated the role of
methyllycaconitine-sensitive, α7-like nAChRs in mediating DS
responses to textured stimuli and apparent motion. We recorded
extracellularly from On–Off DS ganglion cells in rabbit retina
using everted eyecup preparations. Our data provide evidence that
MLA-sensitive nAChRs are involved in mediating directionally selective
responses to apparent motion and to a variety of complex, textured
stimuli such as drifting square-wave gratings, transparent motion, and
second-order motion.
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Affiliation(s)
- B T Reed
- Vision Science Research Center, University of Alabama at Birmingham, Birmingham, AL 35294-4390, USA
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29
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Strang CE, Amthor FR, Keyser KT. Rabbit retinal ganglion cell responses to nicotine can be mediated by beta2-containing nicotinic acetylcholine receptors. Vis Neurosci 2004; 20:651-62. [PMID: 15088718 DOI: 10.1017/s0952523803206076] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Acetylcholine (ACh) affects the response properties of many retinal ganglion cells (GCs) through the activation of nicotinic acetylcholine receptors (nAChRs). To date there have been few studies directly correlating the expression of specific nAChR subtypes with the physiological and morphological characteristics of specific retinal GCs. This study was designed to correlate responses to nicotine application with immunohistochemical evidence of nAChR expression in physiologically and morphologically identified ganglion cells. Extracellular recordings were used to physiologically identify rabbit retinal GCs, based on responses to light stimulation. Cells were then tested for responses to nicotine application and/or for expression of nAChRs, as judged by immunoreactivity to mAb210, an nAChR antibody. The morphologies of many physiologically identified cells were also determined by dye injection. More than three-fourths of ganglion cells tested responded to nicotine application under cobalt-induced synaptic blockade. The nicotine sensitivity was consistent with nAChR immunoreactivity and was also correlated with specific morphological subgroups of GCs. Overall, approximately two-thirds of all physiologically identified GCs that were processed for immunohistochemistry displayed immunoreactivity. In total, 18 of 22 physiologically identified cells demonstrated both sensitivity to nicotine application under synaptic blockade and mAb210 immunoreactivity (mAb210-IR). Thus, mAb210-IR is likely to represent functional nAChRs that can modulate retinal information processing and visual functioning via direct excitation of a number of GC classes.
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30
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Chiao CC, Masland RH. Contextual tuning of direction-selective retinal ganglion cells. Nat Neurosci 2003; 6:1251-2. [PMID: 14595442 DOI: 10.1038/nn1147] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2003] [Accepted: 09/25/2003] [Indexed: 11/09/2022]
Abstract
A direction-selective (DS) retinal ganglion cell responds well to a small object moving within its receptive field center, but less well when there is also a moving stimulus in the surrounding area; this has been described as tuning for local motion. We show here an additional selectivity, such that the surround has less effect if there is a discontinuity--that is, a difference in spatial phase, spatial frequency or velocity--between the center stimulus and that present in the surround.
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Affiliation(s)
- Chuan-Chin Chiao
- Howard Hughes Medical Institute, Massachusetts General Hospital, Harvard Medical School, 50 Blossom Street, Wellman 429, Boston, Massachusetts 02114, USA
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31
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Abstract
Direction-selective retinal ganglion cells (DSGCs) respond to image motion in a "preferred" direction but not the opposite "null" direction. Extracellular spike recordings from rabbit DSGCs suggested that the key mechanism underlying the directional responses is spatially offset inhibition projecting in the null direction. Recent patch-clamp recordings have shown that this inhibition, which acts directly on the DSGC, is already direction selective. Dual recordings established that the inhibition arises from starburst amacrine cells (SBACs) located on the null side of the DSGC but not from those on the preferred side. Thus, for each radially symmetric SBAC, processes pointing in different directions would provide the null-direction inhibition to subtypes of DSGCs with different preferred directions. Ca2+ imaging revealed that the SBAC terminal processes respond more strongly to image motion away from the soma than towards the soma, therefore accounting for the direction selectivity of the inhibitory input to the DSGCs.
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Affiliation(s)
- W Rowland Taylor
- Neurological Sciences Institute, Oregon Health and Science University, 505 NW 185th Avenue, Beaverton, OR 97006, USA.
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32
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Starburst cells nondirectionally facilitate the responses of direction-selective retinal ganglion cells. J Neurosci 2003. [PMID: 12486140 DOI: 10.1523/jneurosci.22-24-10509.2002] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The mechanism of direction selectivity in retinal ganglion cells remains controversial. An important issue is how the starburst amacrine cells, which are known to provide a major synaptic input to the direction-selective ganglion cells, participate in the directional discrimination. Here, we present evidence that the cholinergic outputs of the starburst cells affect the responses of the ganglion cells symmetrically; they provide a feedforward excitation that facilitates the response of the ganglion cells to movement in both the preferred and null directions. This seems to place a constraint on models of the directional discrimination in which the starburst cells participate, namely, that their cholinergic synapses be nondirectional in their effects on the ganglion cells.
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Clifford CWG, Ibbotson MR. Fundamental mechanisms of visual motion detection: models, cells and functions. Prog Neurobiol 2002; 68:409-37. [PMID: 12576294 DOI: 10.1016/s0301-0082(02)00154-5] [Citation(s) in RCA: 140] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Taking a comparative approach, data from a range of visual species are discussed in the context of ideas about mechanisms of motion detection. The cellular basis of motion detection in the vertebrate retina, sub-cortical structures and visual cortex is reviewed alongside that of the insect optic lobes. Special care is taken to relate concepts from theoretical models to the neural circuitry in biological systems. Motion detection involves spatiotemporal pre-filters, temporal delay filters and non-linear interactions. A number of different types of non-linear mechanism such as facilitation, inhibition and division have been proposed to underlie direction selectivity. The resulting direction-selective mechanisms can be combined to produce speed-tuned motion detectors. Motion detection is a dynamic process with adaptation as a fundamental property. The behavior of adaptive mechanisms in motion detection is discussed, focusing on the informational basis of motion adaptation, its phenomenology in human vision, and its cellular basis. The question of whether motion adaptation serves a function or is simply the result of neural fatigue is critically addressed.
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Affiliation(s)
- C W G Clifford
- Colour, Form and Motion Laboratory, Visual Perception Unit, School of Psychology, The University of Sydney, Sydney 2006, NSW, Australia.
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Abstract
The synaptic conductance of the On-Off direction-selective ganglion cells was measured during visual stimulation to determine whether the direction selectivity is a property of the circuitry presynaptic to the ganglion cells or is generated by postsynaptic interaction of excitatory and inhibitory inputs. Three synaptic asymmetries were identified that contribute to the generation of direction-selective responses: (1) a presynaptic mechanism producing stronger excitation in the preferred direction, (2) a presynaptic mechanism producing stronger inhibition in the opposite direction, and (3) postsynaptic interaction of excitation with spatially offset inhibition. Although the on- and off-responses showed the same directional tuning, the off-response was generated by all three mechanisms, whereas the on-response was generated primarily by the two presynaptic mechanisms. The results indicate that, within a single neuron, different strategies are used within distinct dendritic arbors to accomplish the same neural computation.
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Euler T, Detwiler PB, Denk W. Directionally selective calcium signals in dendrites of starburst amacrine cells. Nature 2002; 418:845-52. [PMID: 12192402 DOI: 10.1038/nature00931] [Citation(s) in RCA: 413] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The detection of image motion is fundamental to vision. In many species, unique classes of retinal ganglion cells selectively respond to visual stimuli that move in specific directions. It is not known which retinal cell first performs the neural computations that give rise to directional selectivity in the ganglion cell. A prominent candidate has been an interneuron called the 'starburst amacrine cell'. Using two-photon optical recordings of intracellular calcium concentration, here we find that individual dendritic branches of starburst cells act as independent computation modules. Dendritic calcium signals, but not somatic membrane voltage, are directionally selective for stimuli that move centrifugally from the cell soma. This demonstrates that direction selectivity is computed locally in dendritic branches at a stage before ganglion cells.
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Affiliation(s)
- Thomas Euler
- Max Planck Institute for Medical Research, Jahnstrasse 29, D-69120 Heidelberg, Germany.
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Vaney DI, Pow DV. The dendritic architecture of the cholinergic plexus in the rabbit retina: Selective labeling by glycine accumulation in the presence of sarcosine. J Comp Neurol 2000. [DOI: 10.1002/(sici)1096-9861(20000522)421:1<1::aid-cne1>3.0.co;2-h] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Nguyen LT, Grzywacz NM. Colocalization of choline acetyltransferase and gamma-aminobutyric acid in the developing and adult turtle retinas. J Comp Neurol 2000; 420:527-38. [PMID: 10805925 DOI: 10.1002/(sici)1096-9861(20000515)420:4<527::aid-cne9>3.0.co;2-i] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Acetylcholine and gamma -aminobutyric acid (GABA) are putative neurotransmitters in the adult vertebrate retina. In this study, cells that coexpress choline acetyltransferase (ChAT) and GABA or glutamic acid decarboxylase (GAD) were investigated in turtle retinas from stage 14 (S14) to adulthood by using a double-labeling immunofluorescence technique. ChAT immunoreactivity was observed at S15 and included not only the presumptive starburst cholinergic amacrine cells but also a population in the ganglion cell layer (GCL) that expressed ChAT transiently during the embryonic stages (see the accompanying paper: Nguyen et al. [2000] J. Comp. Neurol. 420:512-526).
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Affiliation(s)
- L T Nguyen
- The Smith-Kettlewell Eye Research Institute, San Francisco, California 94115, USA
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Duarte CB, Santos PF, Carvalho AP. Corelease of two functionally opposite neurotransmitters by retinal amacrine cells: experimental evidence and functional significance. J Neurosci Res 1999; 58:475-9. [PMID: 10533040 DOI: 10.1002/(sici)1097-4547(19991115)58:4<475::aid-jnr1>3.0.co;2-o] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
The Dale's law postulates that a neuron releases the same neurotransmitter from all its branches. In the case of multiple neurotransmitters it would require all transmitters to be released from all branches. The retinal cholinergic amacrine cells contain and release gamma-aminobutyric (GABA) and, therefore, if GABA and acetylcholine (ACh) are released at the same sites, this could mean that amacrine cells simultaneously excite and inhibit postsynaptic cells. Conversely, if the two neurotransmitters are released at different synapses, or if their release is regulated in a distinct manner, they may play different physiological roles. Recent studies carried out in cultured cholinergic amacrine-like neurons showed that Ca(2+)-dependent release of ACh and GABA have a different sensitivity to membrane depolarization, to the effect of blockers of voltage gated Ca(2+) channels (VGCC) and to the effect of presynaptic A(1) adenosine receptors. Therefore, it is proposed that in retinal amacrine cells the Ca(2+)-dependent release of ACh and GABA occurs at distinct cellular locations. The possible nature of these release sites and the physiological significance of this model are discussed in this review.
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Affiliation(s)
- C B Duarte
- Center for Neuroscience of Coimbra, Department of Zoology, University of Coimbra, Coimbra, Portugal.
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The nondiscriminating zone of directionally selective retinal ganglion cells: comparison with dendritic structure and implications for mechanism. J Neurosci 1999. [PMID: 10479705 DOI: 10.1523/jneurosci.19-18-08049.1999] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
We have studied, at high resolution, the sizes and pattern of dendrites of directionally selective retinal ganglion cells in the rabbit. The dendrites had a distinctive pattern of branching. The major dendritic trunks were relatively thick, beginning at approximately 1 micrometer and tapering to approximately 0.5 micrometer in diameter. Higher order dendrites exiting from them generally stepped abruptly to a diameter of 0.4-0.6 micrometer, which they maintained throughout their length. Recording confirmed the existence of a zone within the receptive field, usually occupying 20-25% of its area, where direction of movement was only weakly discriminated. The dendritic arbors of cells, injected with Lucifer yellow after recording, revealed no difference in dendritic structure between the discriminating and nondiscriminating zones. The nondiscriminating zone was located on the preferred side of the receptive field (the side from which movement in the preferred direction originates). This is consistent with a mechanism of direction selectivity based on inhibition generated by movement in the null direction but not with feedforward excitation, as occurs in flies and is postulated in some models of mammalian direction selectivity.
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Brown SP, Masland RH. Costratification of a population of bipolar cells with the direction-selective circuitry of the rabbit retina. J Comp Neurol 1999. [DOI: 10.1002/(sici)1096-9861(19990524)408:1<97::aid-cne7>3.0.co;2-p] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Grzywacz NM, Amthor FR, Merwine DK. Necessity of acetylcholine for retinal directionally selective responses to drifting gratings in rabbit. J Physiol 1998; 512 ( Pt 2):575-81. [PMID: 9763645 PMCID: PMC2231216 DOI: 10.1111/j.1469-7793.1998.575be.x] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
1. A model for retinal directional selectivity postulates that GABAergic inhibition of responses to motions in the null (anti-preferred) direction underlies this selectivity. An alternative model postulates that besides this inhibition, there exists an asymmetric, nicotinic acetylcholine (ACh) input from starburst amacrine cells. It is possible for the latter but not the former model that stimuli could exist such that nicotinic blockade eliminates directional selectivity. Such stimuli would drive the cholinergic but not the GABAergic system well. 2. So far, attempts to eliminate directional selectivity with nicotinic blockade have failed, but they always used isolated, moving bars as the stimulus. We confirmed this failure for On-Off directionally selective (DS) ganglion cells in our preparation of the rabbit's retina. 3. However, while recording from these cells, we discovered that nicotinic blockade eliminated directional selectivity to drifting, low spatial frequency sine- and square-wave gratings. 4. This effect was not just due to the smallness of the responses under nicotinic blockade. NMDA blockade caused even smaller responses, but no loss of directional selectivity. 5. This result is consistent with a two-asymmetric-pathways model of directional selectivity, but inconsistent with an asymmetric-GABA-only model. 6. We conclude that asymmetric nicotinic inputs extend the range of stimuli that can elicit directional selectivity to include moving textures, that is, those with multiple peaks in their spatial luminance profile.
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Affiliation(s)
- N M Grzywacz
- The Smith-Kettlewell Eye Research Institute, 2232 Webster Street, San Francisco, CA 94115, USA.
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