Release from the cone ribbon synapse under bright light conditions can be controlled by the opening of only a few Ca channels
نویسندگان
چکیده
Theodore M. Bartoletti,* Skyler L. Jackman,* Norbert Babai, Aaron J. Mercer, Richard H. Kramer, and Wallace B. Thoreson Department of Ophthalmology and Visual Sciences and Department of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, Nebraska; Department of Neurobiology, Harvard Medical School, Boston, Massachusetts; and Department of Molecular and Cell Biology, University of California-Berkeley, Berkeley, California
منابع مشابه
Release from the cone ribbon synapse under bright light conditions can be controlled by the opening of only a few Ca(2+) channels.
Light hyperpolarizes cone photoreceptors, causing synaptic voltage-gated Ca(2+) channels to open infrequently. To understand neurotransmission under these conditions, we determined the number of L-type Ca(2+) channel openings necessary for vesicle fusion at the cone ribbon synapse. Ca(2+) currents (I(Ca)) were activated in voltage-clamped cones, and excitatory postsynaptic currents (EPSCs) were...
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Mercer AJ, Szalewski RJ, Jackman SL, Van Hook MJ, Thoreson WB. Regulation of presynaptic strength by controlling Ca channel mobility: effects of cholesterol depletion on release at the cone ribbon synapse. J Neurophysiol 107: 3468–3478, 2012. First published March 21, 2012; doi:10.1152/jn.00779.2011.—Synaptic communication requires proper coupling between voltage-gated Ca (CaV) channels and syn...
متن کاملRegulation of presynaptic strength by controlling Ca2+ channel mobility: effects of cholesterol depletion on release at the cone ribbon synapse.
Synaptic communication requires proper coupling between voltage-gated Ca(2+) (Ca(V)) channels and synaptic vesicles. In photoreceptors, L-type Ca(V) channels are clustered close to synaptic ribbon release sites. Although clustered, Ca(V) channels move continuously within a confined domain slightly larger than the base of the ribbon. We hypothesized that expanding Ca(V) channel confinement domai...
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Postsynaptic responses are a product of quantal amplitude (Q), size of the releasable vesicle pool (N), and release probability (P). Voltage-dependent changes in presynaptic Ca(2+) entry alter postsynaptic responses primarily by changing P but have also been shown to influence N. With simultaneous whole cell recordings from cone photoreceptors and horizontal cells in tiger salamander retinal sl...
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Several studies have shown the importance of calcium channels in the development and/or maturation of synapses. The Ca(V)1.4(α(1F)) knockout mouse is a unique model to study the role of calcium channels in photoreceptor synapse formation. It features abnormal ribbon synapses and aberrant cone morphology. We investigated the expression and targeting of several key elements of ribbon synapses and...
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