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Condomitti G, Wierda KD, Schroeder A, Rubio SE, Vennekens KM, Orlandi C, Martemyanov KA, Gounko NV, Savas JN, de Wit J. An Input-Specific Orphan Receptor GPR158-HSPG Interaction Organizes Hippocampal Mossy Fiber-CA3 Synapses. Neuron 2018; 100:201-215.e9. [PMID: 30290982 DOI: 10.1016/j.neuron.2018.08.038] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2017] [Revised: 07/02/2018] [Accepted: 08/29/2018] [Indexed: 12/20/2022]
Abstract
Pyramidal neuron dendrites integrate synaptic input from multiple partners. Different inputs converging on the same dendrite have distinct structural and functional features, but the molecular mechanisms organizing input-specific properties are poorly understood. We identify the orphan receptor GPR158 as a binding partner for the heparan sulfate proteoglycan (HSPG) glypican 4 (GPC4). GPC4 is enriched on hippocampal granule cell axons (mossy fibers), whereas postsynaptic GPR158 is restricted to the proximal segment of CA3 apical dendrites receiving mossy fiber input. GPR158-induced presynaptic differentiation in contacting axons requires cell-surface GPC4 and the co-receptor LAR. Loss of GPR158 increases mossy fiber synapse density but disrupts bouton morphology, impairs ultrastructural organization of active zone and postsynaptic density, and reduces synaptic strength of this connection, while adjacent inputs on the same dendrite are unaffected. Our work identifies an input-specific HSPG-GPR158 interaction that selectively organizes synaptic architecture and function of developing mossy fiber-CA3 synapses in the hippocampus.
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Affiliation(s)
- Giuseppe Condomitti
- VIB Center for Brain & Disease Research, Herestraat 49, 3000 Leuven, Belgium; KU Leuven, Department of Neurosciences, Leuven Brain Institute, Herestraat 49, 3000 Leuven, Belgium
| | - Keimpe D Wierda
- VIB Center for Brain & Disease Research, Herestraat 49, 3000 Leuven, Belgium; KU Leuven, Department of Neurosciences, Leuven Brain Institute, Herestraat 49, 3000 Leuven, Belgium
| | - Anna Schroeder
- VIB Center for Brain & Disease Research, Herestraat 49, 3000 Leuven, Belgium; KU Leuven, Department of Neurosciences, Leuven Brain Institute, Herestraat 49, 3000 Leuven, Belgium
| | - Sara E Rubio
- VIB Center for Brain & Disease Research, Herestraat 49, 3000 Leuven, Belgium; KU Leuven, Department of Neurosciences, Leuven Brain Institute, Herestraat 49, 3000 Leuven, Belgium
| | - Kristel M Vennekens
- VIB Center for Brain & Disease Research, Herestraat 49, 3000 Leuven, Belgium; KU Leuven, Department of Neurosciences, Leuven Brain Institute, Herestraat 49, 3000 Leuven, Belgium
| | - Cesare Orlandi
- Department of Neuroscience, The Scripps Research Institute, Jupiter, FL 33458, USA
| | - Kirill A Martemyanov
- Department of Neuroscience, The Scripps Research Institute, Jupiter, FL 33458, USA
| | - Natalia V Gounko
- VIB Center for Brain & Disease Research, Herestraat 49, 3000 Leuven, Belgium; KU Leuven, Department of Neurosciences, Leuven Brain Institute, Herestraat 49, 3000 Leuven, Belgium; Electron Microscopy Platform & VIB BioImaging Core, Herestraat 49, 3000 Leuven, Belgium
| | - Jeffrey N Savas
- Department of Neurology, Northwestern University, Feinberg School of Medicine, Chicago, IL 60611, USA
| | - Joris de Wit
- VIB Center for Brain & Disease Research, Herestraat 49, 3000 Leuven, Belgium; KU Leuven, Department of Neurosciences, Leuven Brain Institute, Herestraat 49, 3000 Leuven, Belgium.
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Reid CA, Fabian-Fine R, Fine A. Postsynaptic calcium transients evoked by activation of individual hippocampal mossy fiber synapses. J Neurosci 2001; 21:2206-14. [PMID: 11264296 PMCID: PMC6762406] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/19/2023] Open
Abstract
Control of Ca(2+) within dendritic spines is critical for excitatory synaptic function and plasticity, but little is known about Ca(2+) dynamics at thorny excrescences, the complex spines on hippocampal CA3 pyramidal cells contacted by mossy fiber terminals of dentate granule cell axons. We have monitored subthreshold stimulus-dependent postsynaptic Ca(2+) transients in optically and ultrastructurally characterized complex spines and find that such spines can act as discrete units of Ca(2+) response. In contrast to the more common "simple" spines, synaptically evoked Ca(2+) transients at complex spines have only a small NMDA receptor-dependent component and do not involve release of calcium from internal stores. Instead, they result mainly from AMPA receptor-gated Ca(2+) influx through voltage-activated calcium channels on the spine; these channels provide graded amplification of the response of thorny excrescences to individual mossy fiber synaptic events.
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Affiliation(s)
- C A Reid
- Division of Neurophysiology, National Institute for Medical Research, London NW7 1AA, United Kingdom
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