In contrast to conventional synapses, which release neurotransmitter transiently, ribbon synapses formed by photoreceptors and bipolar cells of the retina release neurotransmitter continuously and modulate the rate in response to light. Both modes of release are mediated by synaptic vesicles but probably differ in the regulation of docking and fusion of synaptic vesicles with the plasma membran...

Vesicle release from rod photoreceptors is regulated by Ca(2+) entry through L-type channels located near synaptic ribbons. We characterized sites and kinetics of vesicle release in salamander rods by using total internal reflection fluorescence microscopy to visualize fusion of individual synaptic vesicles. A small number of vesicles were loaded by brief incubation with FM1-43 or a dextran-con...

This study reports the preparation of soft magnetic ribbons of Fe-based amorphous alloys using the single-roller melt-spinning technique. Ribbon width varied from 142 mm to 213 mm and, with a thickness of approximately 22 μm 2 μm. The microstructure and magnetic properties of the ribbons were characterized by differential scanning calorimeter (DSC), X-ray diffraction (XRD), vibrating sample mag...

Solar flare emissions at Hα and EUV/UV wavelengths often appear in the form of two ribbons, which has been regarded as evidence for a typical configuration of solar magnetic reconnection. However, such a ribbon structure has rarely been observed in hard X-rays (HXRs), although it is expected as well. In this letter, we report a ribbon-like HXR source observed with the Reuven Ramaty High Energy ...

The general subunit of all three eukaryotic RNA polymerases, Rpb12, and subunit P of the archaeal enzyme show sequence similarities in their N-terminal zinc ribbon and some highly conserved residues in the C-terminus. We report here that archaeal subunit P under the control of a strong yeast promoter could complement the lethal phenotype of a RPB12 deletion mutant and that subunit Rpb12 from ye...

The auditory inner hair cell (IHC) ribbon synapse operates with an exceptional temporal precision and maintains a high level of neurotransmitter release. However, the molecular mechanisms underlying IHC synaptic exocytosis are largely unknown. We studied otoferlin, a predicted C2-domain transmembrane protein, which is defective in a recessive form of human deafness. We show that otoferlin expre...

Ribbon synapses of sensory neurons are able to sustain high rates of exocytosis in response to maintained depolarization, but it is not known how this is achieved. Using the capacitance technique, we have found that Ca(2+) regulates the supply of releasable vesicles at the ribbon synapse of depolarizing bipolar cells from the retina of goldfish. Ca(2+) had two actions that could be differentiat...

In the vertebrate retina, neuronal circuitry required for visual perception is organized within specific laminae. Photoreceptors convey external visual information to bipolar and horizontal cells at triad ribbon synapses established within the outer plexiform layer (OPL), initiating retinal visual processing. However, the molecular mechanisms that organize these three classes of neuronal proces...

We report the discovery of an entirely new three-dimensional (3D) swimming pattern observed in human and horse sperms. This motion is in the form of 'chiral ribbons', where the planar swing of the sperm head occurs on an osculating plane creating in some cases a helical ribbon and in some others a twisted ribbon. The latter, i.e., the twisted ribbon trajectory, also defines a minimal surface, e...

The photoreceptor ribbon synapse is a highly specialized glutamatergic synapse designed for the continuous flow of synaptic vesicles to the neurotransmitter release site. The molecular mechanisms underlying ribbon synapse formation are poorly understood. We have investigated the role of the presynaptic cytomatrix protein Bassoon, a major component of the photoreceptor ribbon, in a mouse retina ...