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Molecular and Cellular Neuroscience Commons™
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Full-Text Articles in Molecular and Cellular Neuroscience
Synaptic Transmission At The Photoreceptor Ribbon Synapse, Chris Mesnard
Synaptic Transmission At The Photoreceptor Ribbon Synapse, Chris Mesnard
Theses & Dissertations
Synaptic transmission relies on the Ca2+-dependent release of neurotransmitters packaged into synaptic vesicles. Ribbon synapses have the capability to release multiple vesicles at a time in a highly coordinated and synchronized manner. Glutamate release from rod and cone photoreceptor cells involves presynaptic ribbons composed largely of the protein RIBEYE. To examine roles of ribbons in rods and cones, we studied mice in which GCamP3 replaced the B-domain of RIBEYE. We discovered that ribbons were absent from rods and cones of both knock-in mice possessing GCamP3 and conditional RIBEYE knockout mice. Mice lacking ribbons showed reduced temporal resolution and …
Mechanisms Of Calcium-Dependent Neurotransmission In Photoreceptors, Justin J. Grassmeyer
Mechanisms Of Calcium-Dependent Neurotransmission In Photoreceptors, Justin J. Grassmeyer
Theses & Dissertations
Rod and cone photoreceptors initiate vision by transforming light into graded membrane voltage changes that in turn dictate the rate of continuous Ca2+-dependent neurotransmission to postsynaptic neurons. Continuous release relies on synaptic ribbons at photoreceptor active zones, which organize exocytotic proteins and deliver vesicles to release sites near voltage-gated Ca2+ channels. Individual cones possess multiple ribbon synapses at which they contact postsynaptic neurons. We examined heterogeneity in signaling at individual ribbon synapses in salamander cones by measuring the voltage dependence of Ca2+ currents (ICa) and Ca2+ influx at individual ribbon release sites. Ca …
Characteristics Of Exocytosis And Endocytosis In Photoreceptors, Karlene M. Cork
Characteristics Of Exocytosis And Endocytosis In Photoreceptors, Karlene M. Cork
Theses & Dissertations
Photoreceptors signal changes in light intensity to downstream retinal neurons through the exocytosis of glutamate-containing synaptic vesicles. The maintenance of the vesicle exocytosis and endocytosis process is essential for ongoing synaptic signaling. This study investigated the properties of exocytosis and endocytosis in photoreceptors and their role in ongoing neurotransmission.
I used electrophysiology and imaging techniques to study the properties of vesicle exocytosis and endocytosis in photoreceptors. First, we examined baseline release in photoreceptors that occurs in the absence of depolarizing stimulation. We measured mEPSCs in whole cell patch clamp recordings from horizontal cells. After inhibiting Ca2+ influx and efflux …