| Ribbon synapse | |
|---|---|
| Details | |
| Function | Synapse |
| Identifiers | |
| Latin | synapsis fasciolaris |
| TH | H2.00.06.2.00024 |
| Anatomical terms of microanatomy | |
The ribbon synapse is a type of neuronal synapse characterized by the presence of an electron-dense structure, the synaptic ribbon, that holds vesicles close to the active zone.[1] It is characterized by a tight vesicle-calcium channel coupling[2][3] that promotes rapid neurotransmitter release and sustained signal transmission. Ribbon synapses undergo a cycle of exocytosis and endocytosis in response to graded changes of membrane potential. It has been proposed that most ribbon synapses undergo a special type of exocytosis based on coordinated multivesicular release.[4][5][6] This interpretation has recently been questioned at the inner hair cell ribbon synapse, where it has been instead proposed that exocytosis is described by uniquantal (i.e., univesicular) release shaped by a flickering vesicle fusion pore.[7]
These unique features specialize the ribbon synapse to enable extremely fast, precise and sustained neurotransmission, which is critical for the perception of complex senses such as vision and hearing. Ribbon synapses are found in retinal photoreceptor cells, vestibular organ receptors, cochlear hair cells, retinal bipolar cells, and pinealocytes.
The synaptic ribbon is a unique structure at the active zone of the synapse. It is positioned several nanometers away from the pre-synaptic membrane and tethers 100 or more synaptic vesicles.[8] Each pre-synaptic cell can have from 10 to 100 ribbons tethered at the membrane, or a total number of 1000–10000 vesicles in close proximity to active zones.[9] The ribbon synapse was first identified in the retina as a thin, ribbon-like presynaptic projection surrounded by a halo of vesicles[10] using transmission electron microscopy in the 1950s, as the technique was gaining mainstream usage.
- ^ Matthews G, Fuchs P (2010). "The diverse roles of ribbon synapses in sensory neurotransmission". Nat. Rev. Neurosci. 11 (12): 812–22. doi:10.1038/nrn2924. PMC 3065184. PMID 21045860.
- ^ Jarsky T, Tian M, Singer JH (2010). "Nanodomain control of exocytosis is responsible for the signaling capability of a retinal ribbon synapse". J. Neurosci. 30 (36): 11885–95. doi:10.1523/JNEUROSCI.1415-10.2010. PMC 2945284. PMID 20826653.
- ^ Wong AB, Rutherford MA, Gabrielaitis M, Pangrsic T, Göttfert F, Frank T, Michanski S, Hell S, Wolf F, Wichmann C, Moser T (2014). "Developmental refinement of hair cell synapses tightens the coupling of Ca2+ influx to exocytosis". EMBO J. 33 (3): 247–64. doi:10.1002/embj.201387110. PMC 3989618. PMID 24442635.
- ^ Glowatzki, Elisabeth; Fuchs, Paul A. (22 January 2002). "Transmitter release at the hair cell ribbon synapse". Nature Neuroscience. 5 (2): 147–154. doi:10.1038/nn796. PMID 11802170. S2CID 15735147.
- ^ Graydon CW, Cho S, Li GL, Kachar B, von Gersdorff H (2011). "Sharp Ca²⁺ nanodomains beneath the ribbon promote highly synchronous multivesicular release at hair cell synapses". J. Neurosci. 31 (46): 16637–50. doi:10.1523/JNEUROSCI.1866-11.2011. PMC 3235473. PMID 22090491.
- ^ Singer JH, Lassová L, Vardi N, Diamond JS (2004). "Coordinated multivesicular release at a mammalian ribbon synapse". Nat. Neurosci. 7 (8): 826–33. doi:10.1038/nn1280. PMID 15235608. S2CID 13232594.
- ^ Chapochnikov NM, Takago H, Huang CH, Pangršič T, Khimich D, Neef J, Auge E, Göttfert F, Hell SW, Wichmann C, Wolf F, Moser T (2014). "Uniquantal release through a dynamic fusion pore is a candidate mechanism of hair cell exocytosis". Neuron. 83 (6): 1389–403. doi:10.1016/j.neuron.2014.08.003. hdl:11858/00-001M-0000-0024-1DA9-C. PMID 25199706.
- ^ Parsons TD, Sterling P (February 2003). "Synaptic ribbon. Conveyor belt or safety belt?". Neuron. 37 (3): 379–82. doi:10.1016/S0896-6273(03)00062-X. PMID 12575947. S2CID 15161167.
- ^ Lenzi D, Runyeon JW, Crum J, Ellisman MH, Roberts WM (January 1999). "Synaptic vesicle populations in saccular hair cells reconstructed by electron tomography". J. Neurosci. 19 (1): 119–32. doi:10.1523/JNEUROSCI.19-01-00119.1999. PMC 6782356. PMID 9870944.
- ^ DE ROBERTIS, E; FRANCHI, CM (25 May 1956). "Electron microscope observations on synaptic vesicles in synapses of the retinal rods and cones". The Journal of Biophysical and Biochemical Cytology. 2 (3): 307–18. doi:10.1083/jcb.2.3.307. PMC 2223974. PMID 13331963.