Learn More
The ribbon complex of retinal photoreceptor synapses represents a specialization of the cytomatrix at the active zone (CAZ) present at conventional synapses. In mice deficient for the CAZ protein Bassoon, ribbons are not anchored to the presynaptic membrane but float freely in the cytoplasm. Exploiting this phenotype, we dissected the molecular structure of(More)
Hearing relies on faithful synaptic transmission at the ribbon synapse of cochlear inner hair cells (IHCs). At present, the function of presynaptic ribbons at these synapses is still largely unknown. Here we show that anchoring of IHC ribbons is impaired in mouse mutants for the presynaptic scaffolding protein Bassoon. The lack of active-zone-anchored(More)
Exocytosis of neurotransmitter from synaptic vesicles is restricted to specialized sites of the presynaptic plasma membrane called active zones. A complex cytomatrix of proteins exclusively assembled at active zones, the CAZ, is thought to form a molecular scaffold that organizes neurotransmitter release sites. Here, we have analyzed synaptic targeting and(More)
PURPOSE Photoreceptor ribbon synapses translate light-dependent changes of membrane potential into graded transmitter release via L-type voltage-dependent calcium channel (VDCC) activity. Functional abnormalities (e.g., a reduced electroretinogram b-wave), arising from mutations of presynaptic proteins, such as Bassoon and the VDCCalpha1 subunit Cacna1f,(More)
Protein synthesis is a dynamic process that tunes the cellular proteome in response to internal and external demands. Metabolic labeling approaches identify the general proteomic response but cannot visualize specific newly synthesized proteins within cells. Here we describe a technique that couples noncanonical amino acid tagging or puromycylation with the(More)
Vision is a highly complex task that involves several steps of parallel information processing in various areas of the central nervous system. Complex processing of visual signals occurs as early as at the retina, the first stage in the visual system. Various aspects of visual information are transmitted in parallel from the photoreceptors (the input(More)
The retinal photoreceptor ribbon synapse is a chemical synapse structurally and functionally specialized for the tonic release of neurotransmitter. It is characterized by the presynaptic ribbon, an electron-dense organelle at the active zone covered by hundreds of synaptic vesicles. In conventional synapses, dense-core transport vesicles carrying a set of(More)
Bassoon is a 420-kDa presynaptic cytomatrix protein potentially involved in the structural organization of neurotransmitter release sites. In this study, we have investigated a possible role for Bassoon in synaptogenesis and in defining synaptic vesicle recycling sites. We find that it is expressed at early stages of neuronal differentiation in which it is(More)
Immunocytochemical discrimination of distinct bipolar cell types in the mouse retina is a prerequisite for analyzing retinal circuitry in wild-type and transgenic mice. Here we demonstrate that among the more than 10 anatomically defined mouse bipolar cell types, type 4 bipolar cells are specifically recognized by anti-calsenilin antibodies. Axon terminals(More)
PURPOSE Photoreceptor ribbon synapses translate light-dependent changes of membrane potential into graded transmitter release over several orders of magnitude in intensity. A specialized organelle at the active zone--the synaptic ribbon--is a key player in this process, and it is well known that the ribbon undergoes illumination and thus activity-dependent(More)