1
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Adhikari P, Uprety S, Feigl B, Zele AJ. Melanopsin-mediated amplification of cone signals in the human visual cortex. Proc Biol Sci 2024; 291:20232708. [PMID: 38808443 DOI: 10.1098/rspb.2023.2708] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2023] [Accepted: 05/02/2024] [Indexed: 05/30/2024] Open
Abstract
The ambient daylight variation is coded by melanopsin photoreceptors and their luxotonic activity increases towards midday when colour temperatures are cooler, and irradiances are higher. Although melanopsin and cone photoresponses can be mediated via separate pathways, the connectivity of melanopsin cells across all levels of the retina enables them to modify cone signals. The downstream effects of melanopsin-cone interactions on human vision are however, incompletely understood. Here, we determined how the change in daytime melanopsin activation affects the human cone pathway signals in the visual cortex. A 5-primary silent-substitution method was developed to evaluate the dependence of cone-mediated signals on melanopsin activation by spectrally tuning the lights and stabilizing the rhodopsin activation under a constant cone photometric luminance. The retinal (white noise electroretinogram) and cortical responses (visual evoked potential) were simultaneously recorded with the photoreceptor-directed lights in 10 observers. By increasing the melanopsin activation, a reverse response pattern was observed with cone signals being supressed in the retina by 27% (p = 0.03) and subsequently amplified by 16% (p = 0.01) as they reach the cortex. We infer that melanopsin activity can amplify cone signals at sites distal to retinal bipolar cells to cause a decrease in the psychophysical Weber fraction for cone vision.
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Affiliation(s)
- Prakash Adhikari
- Centre for Vision and Eye Research, Queensland University of Technology (QUT), Brisbane, Queensland 4059, Australia
| | - Samir Uprety
- Centre for Vision and Eye Research, Queensland University of Technology (QUT), Brisbane, Queensland 4059, Australia
| | - Beatrix Feigl
- Centre for Vision and Eye Research, Queensland University of Technology (QUT), Brisbane, Queensland 4059, Australia
- School of Biomedical Sciences, Queensland University of Technology (QUT), Brisbane, Queensland 4059, Australia
- Queensland Eye Institute, Brisbane, Queensland 4101, Australia
| | - Andrew J Zele
- Centre for Vision and Eye Research, Queensland University of Technology (QUT), Brisbane, Queensland 4059, Australia
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2
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Cortese K, Gagliani MC, Raiteri L. Interactions between Glycine and Glutamate through Activation of Their Transporters in Hippocampal Nerve Terminals. Biomedicines 2023; 11:3152. [PMID: 38137373 PMCID: PMC10740625 DOI: 10.3390/biomedicines11123152] [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: 10/13/2023] [Revised: 11/14/2023] [Accepted: 11/17/2023] [Indexed: 12/24/2023] Open
Abstract
Evidence supports the pathophysiological relevance of crosstalk between the neurotransmitters Glycine and Glutamate and their close interactions; some reports even support the possibility of Glycine-Glutamate cotransmission in central nervous system (CNS) areas, including the hippocampus. Functional studies with isolated nerve terminals (synaptosomes) permit us to study transporter-mediated interactions between neurotransmitters that lead to the regulation of transmitter release. Our main aims here were: (i) to investigate release-regulating, transporter-mediated interactions between Glycine and Glutamate in hippocampal nerve terminals and (ii) to determine the coexistence of transporters for Glycine and Glutamate in these terminals. Purified synaptosomes, analyzed at the ultrastructural level via electron microscopy, were used as the experimental model. Mouse hippocampal synaptosomes were prelabeled with [3H]D-Aspartate or [3H]Glycine; the release of radiolabeled tracers was monitored with the superfusion technique. The main findings were that (i) exogenous Glycine stimulated [3H]D-Aspartate release, partly by activation of GlyT1 and in part, unusually, through GlyT2 transporters and that (ii) D-Aspartate stimulated [3H]glycine release by a process that was sensitive to Glutamate transporter blockers. Based on the features of the experimental model used, it is suggested that functional transporters for Glutamate and Glycine coexist in a small subset of hippocampal nerve terminals, a condition that may also be compatible with cotransmission; glycinergic and glutamatergic transporters exhibit different functions and mediate interactions between the neurotransmitters. It is hoped that increased information on Glutamate-Glycine interactions in different areas, including the hippocampus, will contribute to a better knowledge of drugs acting at "glycinergic" targets, currently under study in relation with different CNS pathologies.
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Affiliation(s)
- Katia Cortese
- Department of Experimental Medicine (DIMES), Cellular Electron Microscopy Lab, University of Genoa, 16132 Genoa, Italy; (K.C.); (M.C.G.)
| | - Maria Cristina Gagliani
- Department of Experimental Medicine (DIMES), Cellular Electron Microscopy Lab, University of Genoa, 16132 Genoa, Italy; (K.C.); (M.C.G.)
| | - Luca Raiteri
- Department of Pharmacy (DIFAR), Pharmacology and Toxicology Section, University of Genoa, 16148 Genoa, Italy
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3
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Wallace ML, Sabatini BL. Synaptic and circuit functions of multitransmitter neurons in the mammalian brain. Neuron 2023; 111:2969-2983. [PMID: 37463580 PMCID: PMC10592565 DOI: 10.1016/j.neuron.2023.06.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2023] [Revised: 05/31/2023] [Accepted: 06/08/2023] [Indexed: 07/20/2023]
Abstract
Neurons in the mammalian brain are not limited to releasing a single neurotransmitter but often release multiple neurotransmitters onto postsynaptic cells. Here, we review recent findings of multitransmitter neurons found throughout the mammalian central nervous system. We highlight recent technological innovations that have made the identification of new multitransmitter neurons and the study of their synaptic properties possible. We also focus on mechanisms and molecular constituents required for neurotransmitter corelease at the axon terminal and synaptic vesicle, as well as some possible functions of multitransmitter neurons in diverse brain circuits. We expect that these approaches will lead to new insights into the mechanism and function of multitransmitter neurons, their role in circuits, and their contribution to normal and pathological brain function.
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Affiliation(s)
- Michael L Wallace
- Department of Anatomy and Neurobiology, Boston University Chobanian & Avedisian School of Medicine, Boston, MA, USA.
| | - Bernardo L Sabatini
- Howard Hughes Medical Institute, Department of Neurobiology, Harvard Medical School, Boston, MA, USA
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4
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Mani A, Yang X, Zhao TA, Leyrer ML, Schreck D, Berson DM. A circuit suppressing retinal drive to the optokinetic system during fast image motion. Nat Commun 2023; 14:5142. [PMID: 37612305 PMCID: PMC10447436 DOI: 10.1038/s41467-023-40527-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2022] [Accepted: 07/26/2023] [Indexed: 08/25/2023] Open
Abstract
Optokinetic nystagmus (OKN) assists stabilization of the retinal image during head rotation. OKN is driven by ON direction selective retinal ganglion cells (ON DSGCs), which encode both the direction and speed of global retinal slip. The synaptic circuits responsible for the direction selectivity of ON DSGCs are well understood, but those sculpting their slow-speed preference remain enigmatic. Here, we probe this mechanism in mouse retina through patch clamp recordings, functional imaging, genetic manipulation, and electron microscopic reconstructions. We confirm earlier evidence that feedforward glycinergic inhibition is the main suppressor of ON DSGC responses to fast motion, and reveal the source for this inhibition-the VGluT3 amacrine cell, a dual neurotransmitter, excitatory/inhibitory interneuron. Together, our results identify a role for VGluT3 cells in limiting the speed range of OKN. More broadly, they suggest VGluT3 cells shape the response of many retinal cell types to fast motion, suppressing it in some while enhancing it in others.
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Affiliation(s)
- Adam Mani
- Department of Neuroscience, Brown University, Providence, RI, USA
| | - Xinzhu Yang
- Department of Neuroscience, Brown University, Providence, RI, USA
| | - Tiffany A Zhao
- Department of Neuroscience, Brown University, Providence, RI, USA
| | - Megan L Leyrer
- Department of Neuroscience, Brown University, Providence, RI, USA
| | - Daniel Schreck
- Department of Neuroscience, Brown University, Providence, RI, USA
| | - David M Berson
- Department of Neuroscience, Brown University, Providence, RI, USA.
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5
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Uprety S, Adhikari P, Feigl B, Zele AJ. Melanopsin photoreception differentially modulates rod-mediated and cone-mediated human temporal vision. iScience 2022; 25:104529. [PMID: 35754721 PMCID: PMC9218364 DOI: 10.1016/j.isci.2022.104529] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2022] [Revised: 05/04/2022] [Accepted: 05/30/2022] [Indexed: 11/17/2022] Open
Abstract
To evaluate the nature of interactions between visual pathways transmitting the slower melanopsin and faster rod and cone signals, we implement a temporal phase summation paradigm in human observers using photoreceptor-directed stimuli. We show that melanopsin stimulation interacts with and alters both rod-mediated and cone-mediated vision regardless of whether it is perceptually visible or not. Melanopsin-rod interactions result in either inhibitory or facilitatory summation depending on the temporal frequency and photoreceptor pathway contrast sensitivity. Moreover, by isolating rod vision, we reveal a bipartite intensity response property of the rod pathway in photopic lighting that extends its operational range at lower frequencies to beyond its classic saturation limits but at the expense of attenuating sensitivity at higher frequencies. In comparison, melanopsin-cone interactions always lead to facilitation. These interactions can be described by linear or probability summations and potentially involve multiple intraretinal and visual cortical pathways to set human visual contrast sensitivity. Melanopsin ipRGCs support vision independent of the rod and cone signals Rod pathways mediate robust visual responses in daylight Temporal contrast sensitivity is contingent on the melanopsin excitation level Visual performance is collectively regulated by melanopsin, rod and cone pathways
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Affiliation(s)
- Samir Uprety
- Centre for Vision and Eye Research, Queensland University of Technology (QUT), Brisbane, QLD 4059, Australia.,School of Optometry and Vision Science, Queensland University of Technology (QUT), Brisbane, QLD 4059, Australia
| | - Prakash Adhikari
- Centre for Vision and Eye Research, Queensland University of Technology (QUT), Brisbane, QLD 4059, Australia.,School of Optometry and Vision Science, Queensland University of Technology (QUT), Brisbane, QLD 4059, Australia
| | - Beatrix Feigl
- Centre for Vision and Eye Research, Queensland University of Technology (QUT), Brisbane, QLD 4059, Australia.,School of Biomedical Sciences, Queensland University of Technology (QUT), Brisbane, QLD 4059, Australia.,Queensland Eye Institute, Brisbane, QLD 4101, Australia
| | - Andrew J Zele
- Centre for Vision and Eye Research, Queensland University of Technology (QUT), Brisbane, QLD 4059, Australia.,School of Optometry and Vision Science, Queensland University of Technology (QUT), Brisbane, QLD 4059, Australia
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6
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Cifuentes F, Morales MA. Functional Implications of Neurotransmitter Segregation. Front Neural Circuits 2021; 15:738516. [PMID: 34720888 PMCID: PMC8548464 DOI: 10.3389/fncir.2021.738516] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2021] [Accepted: 09/21/2021] [Indexed: 11/13/2022] Open
Abstract
Here, we present and discuss the characteristics and properties of neurotransmitter segregation, a subtype of neurotransmitter cotransmission. We review early evidence of segregation and discuss its properties, such as plasticity, while placing special emphasis on its probable functional implications, either in the central nervous system (CNS) or the autonomic nervous system. Neurotransmitter segregation is a process by which neurons separately route transmitters to independent and distant or to neighboring neuronal processes; it is a plastic phenomenon that changes according to synaptic transmission requirements and is regulated by target-derived signals. Distant neurotransmitter segregation in the CNS has been shown to be related to an autocrine/paracrine function of some neurotransmitters. In retinal amacrine cells, segregation of acetylcholine (ACh) and GABA, and glycine and glutamate to neighboring terminals has been related to the regulation of the firing rate of direction-selective ganglion cells. In the rat superior cervical ganglion, segregation of ACh and GABA to neighboring varicosities shows a heterogeneous regional distribution, which is correlated to a similar regional distribution in transmission strength. We propose that greater segregation of ACh and GABA produces less GABAergic inhibition, strengthening ganglionic transmission. Segregation of ACh and GABA varies in different physiopathological conditions; specifically, segregation increases in acute sympathetic hyperactivity that occurs in cold stress, does not vary in chronic hyperactivity that occurs in hypertension, and rises in early ages of normotensive and hypertensive rats. Given this, we propose that variations in the extent of transmitter segregation may contribute to the alteration of neural activity that occurs in some physiopathological conditions and with age.
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Affiliation(s)
- Fredy Cifuentes
- Departamento de Biología Celular y Fisiología, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Miguel Angel Morales
- Departamento de Biología Celular y Fisiología, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Mexico City, Mexico
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7
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Bordt AS, Patterson SS, Girresch RJ, Perez D, Tseng L, Anderson JR, Mazzaferri MA, Kuchenbecker JA, Gonzales-Rojas R, Roland A, Tang C, Puller C, Chuang AZ, Ogilvie JM, Neitz J, Marshak DW. Synaptic inputs to broad thorny ganglion cells in macaque retina. J Comp Neurol 2021; 529:3098-3111. [PMID: 33843050 DOI: 10.1002/cne.25156] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2020] [Revised: 03/22/2021] [Accepted: 04/05/2021] [Indexed: 12/26/2022]
Abstract
In primates, broad thorny retinal ganglion cells are highly sensitive to small, moving stimuli. They have tortuous, fine dendrites with many short, spine-like branches that occupy three contiguous strata in the middle of the inner plexiform layer. The neural circuits that generate their responses to moving stimuli are not well-understood, and that was the goal of this study. A connectome from central macaque retina was generated by serial block-face scanning electron microscopy, a broad thorny cell was reconstructed, and its synaptic inputs were analyzed. It received fewer than 2% of its inputs from both ON and OFF types of bipolar cells; the vast majority of its inputs were from amacrine cells. The presynaptic amacrine cells were reconstructed, and seven types were identified based on their characteristic morphology. Two types of narrow-field cells, knotty bistratified Type 1 and wavy multistratified Type 2, were identified. Two types of medium-field amacrine cells, ON starburst and spiny, were also presynaptic to the broad thorny cell. Three types of wide-field amacrine cells, wiry Type 2, stellate wavy, and semilunar Type 2, also made synapses onto the broad thorny cell. Physiological experiments using a macaque retinal preparation in vitro confirmed that broad thorny cells received robust excitatory input from both the ON and the OFF pathways. Given the paucity of bipolar cell inputs, it is likely that amacrine cells provided much of the excitatory input, in addition to inhibitory input.
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Affiliation(s)
- Andrea S Bordt
- Department of Neurobiology and Anatomy, McGovern Medical School, Houston, Texas, USA.,Department of Ophthalmology, University of Washington, Seattle, Washington, USA
| | - Sara S Patterson
- Center for Visual Science, University of Rochester, Rochester, New York, USA
| | - Rebecca J Girresch
- Department of Biology, Saint Louis University, Saint Louis, Missouri, USA
| | - Diego Perez
- Department of Neurobiology and Anatomy, McGovern Medical School, Houston, Texas, USA
| | - Luke Tseng
- Department of Neurobiology and Anatomy, McGovern Medical School, Houston, Texas, USA
| | - James R Anderson
- John A. Moran Eye Center, University of Utah, Salt Lake City, Utah, USA
| | - Marcus A Mazzaferri
- Department of Ophthalmology, University of Washington, Seattle, Washington, USA
| | | | | | - Ashley Roland
- Department of BioSciences, Rice University, Houston, Texas, USA
| | - Charis Tang
- Department of BioSciences, Rice University, Houston, Texas, USA
| | - Christian Puller
- Department of Ophthalmology, University of Washington, Seattle, Washington, USA.,Department of Neuroscience, Carl von Ossietzky University, Oldenburg, Germany
| | - Alice Z Chuang
- Department of Ophthalmology and Visual Science, McGovern Medical School, Houston, Texas, USA
| | | | - Jay Neitz
- Department of Ophthalmology, University of Washington, Seattle, Washington, USA
| | - David W Marshak
- Department of Neurobiology and Anatomy, McGovern Medical School, Houston, Texas, USA
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8
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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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9
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Trudeau LE, El Mestikawy S. Glutamate Cotransmission in Cholinergic, GABAergic and Monoamine Systems: Contrasts and Commonalities. Front Neural Circuits 2018; 12:113. [PMID: 30618649 PMCID: PMC6305298 DOI: 10.3389/fncir.2018.00113] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2018] [Accepted: 12/03/2018] [Indexed: 11/13/2022] Open
Abstract
Multiple discoveries made since the identification of vesicular glutamate transporters (VGLUTs) two decades ago revealed that many neuronal populations in the brain use glutamate in addition to their "primary" neurotransmitter. Such a mode of cotransmission has been detected in dopamine (DA), acetylcholine (ACh), serotonin (5-HT), norepinephrine (NE) and surprisingly even in GABA neurons. Interestingly, work performed by multiple groups during the past decade suggests that the use of glutamate as a cotransmitter takes different forms in these different populations of neurons. In the present review, we will provide an overview of glutamate cotransmission in these different classes of neurons, highlighting puzzling differences in: (1) the proportion of such neurons expressing a VGLUT in different brain regions and at different stages of development; (2) the sub-cellular localization of the VGLUT; (3) the localization of the VGLUT in relation to the neurons' other vesicular transporter; and (4) the functional role of glutamate cotransmission.
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Affiliation(s)
- Louis-Eric Trudeau
- CNS Research Group, Department of Pharmacology and Physiology, Department of Neurosciences, Faculty of Medicine, Université de Montréal, Montreal, QC, Canada
| | - Salah El Mestikawy
- Department of Psychiatry, Faculty of Medicine, Douglas Mental Health University Institute, McGill University, Montreal, QC, Canada.,Sorbonne Universités, Université Pierre et Marie Curie UM 119-CNRS UMR 8246-INSERM U1130, Neurosciences Paris Seine-Institut de Biologie Paris Seine (NPS-IBPS), Paris, France
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10
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Abstract
Amacrine cells are a diverse set of local circuit neurons of the inner retina, and they all release either GABA or glycine, amino acid neurotransmitters that are generally inhibitory. But some types of amacrine cells have another function besides inhibiting other neurons. One glycinergic amacrine cell, the Aii type, excites a subset of bipolar cells via extensive gap junctions while inhibiting others at chemical synapses. Many types of GABAergic amacrine cells also release monoamines, acetylcholine, or neuropeptides. There is now good evidence that another type of amacrine cell releases glycine at some of its synapses and releases the excitatory amino acid glutamate at others. The glutamatergic synapses are made onto a subset of retinal ganglion cells and amacrine cells and have the asymmetric postsynaptic densities characteristic of central excitatory synapses. The glycinergic synapses are made onto other types of ganglion cells and have the symmetric postsynaptic densities characteristic of central inhibitory synapses. These amacrine cells, which contain vesicular glutamate transporter 3, will be the focus of this brief review.
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11
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Local synaptic integration enables ON-OFF asymmetric and layer-specific visual information processing in vGluT3 amacrine cell dendrites. Proc Natl Acad Sci U S A 2017; 114:11518-11523. [PMID: 28973895 DOI: 10.1073/pnas.1711622114] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
A basic scheme of neuronal organization in the mammalian retina is the segregation of ON and OFF pathways in the inner plexiform layer (IPL), where glutamate is released from ON and OFF bipolar cell terminals in separate inner (ON) and outer (OFF) sublayers in response to light intensity increments and decrements, respectively. However, recent studies have found that vGluT3-expressing glutamatergic amacrine cells (GACs) generate ON-OFF somatic responses and release glutamate onto both ON and OFF ganglion cell types, raising the possibility of crossover excitation in violation of the canonical ON-OFF segregation scheme. To test this possibility, we recorded light-evoked Ca2+ responses from dendrites of individual GACs infected with GCaMP6s in mouse. Under two-photon imaging, a single GAC generated rectified local dendritic responses, showing ON-dominant responses in ON sublayers and OFF-dominant responses in OFF sublayers. This unexpected ON-OFF segregation within a small-field amacrine cell arose from local synaptic processing, mediated predominantly by synaptic inhibition. Multiple forms of synaptic inhibition compartmentalized the GAC dendritic tree and endowed all dendritic varicosities with a small-center, strong-surround receptive field, which varied in receptive field size and degree of ON-OFF asymmetry with IPL depth. The results reveal a form of short-range dendritic autonomy that enables a small-field, dual-transmitter amacrine cell to process diverse dendritic functions in a stratification level- and postsynaptic target-specific manner, while preserving the fundamental ON-OFF segregation scheme for parallel visual processing and high spatial resolution for small object motion and uniformity detection.
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12
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Bordt AS, Long Y, Kouyama N, Yamada ES, Hannibal J, Marshak DW. Wavy multistratified amacrine cells in the monkey retina contain immunoreactive secretoneurin. Peptides 2017. [PMID: 28641988 PMCID: PMC5556933 DOI: 10.1016/j.peptides.2017.06.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The goals of this study were to describe the morphology, neurotransmitter content and synaptic connections of neurons in primate retinas that contain the neuropeptide secretoneurin. Amacrine cells were labeled with antibodies to secretoneurin in macaque and baboon retinas. Their processes formed three distinct plexuses in the inner plexiform layer: one in the outermost stratum, one in the center and one in the innermost stratum. In light microscopic double immunolabeling experiments, GABA was colocalized with secretoneurin in these cells, but glycine transporter 1 and Substance P were not. ON bipolar cell axon terminals labeled with antibody to the cholecystokinin precursor, G6-gly, have ON responses to stimulation of short wavelength sensitive (S) cones. Axons of these bipolar cells made contacts with amacrine cell dendrites containing secretoneurin. Secretoneurin-IR amacrine cells also made contacts with retinal ganglion cell dendrites labeled with antibody to the photopigment melanopsin, which have OFF responses to stimulation of S cones. Using electron microscopic immunolabeling, 436 synapses from macaque retina were analyzed. Axons from bipolar cells were identified by their characteristic synaptic ribbons; their synaptic densities were asymmetric like those of excitatory synapses in the brain. Amacrine cells made and received conventional synapses with symmetric synaptic densities, like those of inhibitory synapses in the brain. Ganglion cell dendrites were identified by their absence of presynaptic specializations; they received inputs from both amacrine cells and bipolar cells. The majority of inputs to the secretoneurin-IR amacrine cells were from other amacrine cells, but they also received 21% of their input from bipolar cells. They directed most of their output, 54%, to amacrine cells, but there were many synapses onto bipolar cell axons and ganglion cell dendrites, as well. The synaptic connections were very similar in the three plexuses with one notable exception; output synapses to bipolar cells were significantly less common in the innermost one, where the S-ON bipolar cells terminate. Taken together, these findings suggest that the secretoneurin-IR amacrine cells in primates receive excitatory input from S-ON bipolar cells and, in turn, inhibit intrinsically photosensitive retinal ganglion cells.
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Affiliation(s)
- Andrea S Bordt
- Department of Neurobiology and Anatomy, McGovern Medical School, Houston, TX, USA
| | - Ye Long
- Department of Neurobiology and Anatomy, McGovern Medical School, Houston, TX, USA; Department of Ophthalmology and Visual Science, McGovern Medical School, Houston, TX, USA
| | - Nobuo Kouyama
- Nursing School, Tokyo Women's Medical University, Shizuoka, Japan
| | - Elizabeth S Yamada
- Institute of Biological Sciences, Federal University of Pará, Belem, Brazil
| | - Jens Hannibal
- Department of Clinical Biochemistry, Bispebjerg Hospital, Copenhagen University, Copenhagen, Denmark
| | - David W Marshak
- Department of Neurobiology and Anatomy, McGovern Medical School, Houston, TX, USA; Department of Ophthalmology and Visual Science, McGovern Medical School, Houston, TX, USA.
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13
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Sinha R, Hoon M, Baudin J, Okawa H, Wong ROL, Rieke F. Cellular and Circuit Mechanisms Shaping the Perceptual Properties of the Primate Fovea. Cell 2017; 168:413-426.e12. [PMID: 28129540 PMCID: PMC5298833 DOI: 10.1016/j.cell.2017.01.005] [Citation(s) in RCA: 101] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2016] [Revised: 11/21/2016] [Accepted: 01/05/2017] [Indexed: 10/20/2022]
Abstract
The fovea is a specialized region of the retina that dominates the visual perception of primates by providing high chromatic and spatial acuity. While the foveal and peripheral retina share a similar core circuit architecture, they exhibit profound functional differences whose mechanisms are unknown. Using intracellular recordings and structure-function analyses, we examined the cellular and synaptic underpinnings of the primate fovea. Compared to peripheral vision, the fovea displays decreased sensitivity to rapid variations in light inputs; this difference is reflected in the responses of ganglion cells, the output cells of the retina. Surprisingly, and unlike in the periphery, synaptic inhibition minimally shaped the responses of foveal midget ganglion cells. This difference in inhibition cannot however, explain the differences in the temporal sensitivity of foveal and peripheral midget ganglion cells. Instead, foveal cone photoreceptors themselves exhibited slower light responses than peripheral cones, unexpectedly linking cone signals to perceptual sensitivity.
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Affiliation(s)
- Raunak Sinha
- Department of Physiology and Biophysics, University of Washington, Seattle, Washington 98195, USA; Howard Hughes Medical Institute, University of Washington, Seattle, Washington 98195, USA.
| | - Mrinalini Hoon
- Department of Biological Structure, University of Washington, Seattle, Washington 98195, USA.
| | - Jacob Baudin
- Department of Physiology and Biophysics, University of Washington, Seattle, Washington 98195, USA; Howard Hughes Medical Institute, University of Washington, Seattle, Washington 98195, USA
| | - Haruhisa Okawa
- Department of Biological Structure, University of Washington, Seattle, Washington 98195, USA
| | - Rachel O L Wong
- Department of Biological Structure, University of Washington, Seattle, Washington 98195, USA
| | - Fred Rieke
- Department of Physiology and Biophysics, University of Washington, Seattle, Washington 98195, USA; Howard Hughes Medical Institute, University of Washington, Seattle, Washington 98195, USA.
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Segregated Glycine-Glutamate Co-transmission from vGluT3 Amacrine Cells to Contrast-Suppressed and Contrast-Enhanced Retinal Circuits. Neuron 2016; 90:27-34. [PMID: 26996083 DOI: 10.1016/j.neuron.2016.02.023] [Citation(s) in RCA: 62] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2015] [Revised: 12/06/2015] [Accepted: 01/28/2016] [Indexed: 02/05/2023]
Abstract
Since the introduction of Dale's principle of "one neuron releases one transmitter at all its synapses," a growing number of exceptions to this principle have been identified. While the concept of neurotransmitter co-release by a single neuron is now well accepted, the specific synaptic circuitry and functional advantage of co-neurotransmission remain poorly understood in general. Here we report Ca(2+)-dependent co-release of a new combination of inhibitory and excitatory neurotransmitters, namely, glycine and glutamate, by the vGluT3-expressing amacrine cell (GAC) in the mouse retina. GACs selectively make glycinergic synapses with uniformity detectors (UDs) and provide a major inhibitory drive that underlies the suppressed-by-contrast trigger feature of UDs. Meanwhile, GACs release glutamate to excite OFF alpha ganglion cells and a few other nonlinear, contrast-sensitive ganglion cells. This coordinated inhibition and excitation of two separate neuronal circuits by a single interneuron suggests a unique advantage in differential detection of visual field uniformity and contrast.
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Masri RA, Percival KA, Koizumi A, Martin PR, Grünert U. Connectivity between the OFF bipolar type DB3a and six types of ganglion cell in the marmoset retina. J Comp Neurol 2015; 524:1839-58. [PMID: 26559914 DOI: 10.1002/cne.23925] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2015] [Revised: 10/12/2015] [Accepted: 11/09/2015] [Indexed: 12/31/2022]
Abstract
Parallel visual pathways originate at the first synapse in the retina, where cones make connections with cone bipolar cells that in turn contact ganglion cells. There are more ganglion cell types than bipolar types, suggesting that there must be divergence from bipolar to ganglion cells. Here we analyze the contacts between an OFF bipolar type (DB3a) and six ganglion cell types in the retina of the marmoset monkey (Callithrix jacchus). Ganglion cells were transfected via particle-mediated gene transfer of an expression plasmid for the postsynaptic density 95-green fluorescent protein (PSD95-GFP), and DB3a cells were labeled via immunohistochemistry. Ganglion cell types that fully or partially costratified with DB3a cells included OFF parasol, OFF midget, broad thorny, recursive bistratified, small bistratified, and large bistratified cells. On average, the number of DB3a contacts to parasol cells (18 contacts per axon terminal) is higher than that to other ganglion cell types (between four and seven contacts). We estimate that the DB3a output to OFF parasol cells accounts for at least 30% of the total DB3a output. Furthermore, we found that OFF parasol cells receive approximately 20% of their total bipolar input from DB3a cells, suggesting that other diffuse bipolar types also provide input to OFF parasol cells. We conclude that DB3a cells preferentially contact OFF parasol cells but also provide input to other ganglion cell types.
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Affiliation(s)
- Rania A Masri
- Department of Ophthalmology and Save Sight Institute, The University of Sydney, Sydney, New South Wales, 2000, Australia
| | - Kumiko A Percival
- Department of Ophthalmology and Save Sight Institute, The University of Sydney, Sydney, New South Wales, 2000, Australia
| | - Amane Koizumi
- National Institutes of Natural Sciences, Tokyo, Japan
| | - Paul R Martin
- Department of Ophthalmology and Save Sight Institute, The University of Sydney, Sydney, New South Wales, 2000, Australia.,Australian Research Council Centre of Excellence for Integrative Brain Function, The University of Sydney, Sydney, New South Wales, 2000, Australia.,School of Medical Sciences, The University of Sydney, Sydney, New South Wales, 2000, Australia
| | - Ulrike Grünert
- Department of Ophthalmology and Save Sight Institute, The University of Sydney, Sydney, New South Wales, 2000, Australia.,Australian Research Council Centre of Excellence for Integrative Brain Function, The University of Sydney, Sydney, New South Wales, 2000, Australia.,School of Medical Sciences, The University of Sydney, Sydney, New South Wales, 2000, Australia
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