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Munc13-independent vesicle priming at mouse photoreceptor ribbon synapses.
- Source :
-
The Journal of neuroscience : the official journal of the Society for Neuroscience [J Neurosci] 2012 Jun 06; Vol. 32 (23), pp. 8040-52. - Publication Year :
- 2012
-
Abstract
- Munc13 proteins are essential regulators of exocytosis. In hippocampal glutamatergic neurons, the genetic deletion of Munc13s results in the complete loss of primed synaptic vesicles (SVs) in direct contact with the presynaptic active zone membrane, and in a total block of neurotransmitter release. Similarly drastic consequences of Munc13 loss are detectable in hippocampal and striatal GABAergic neurons. We show here that, in the adult mouse retina, the two Munc13-2 splice variants bMunc13-2 and ubMunc13-2 are selectively localized to conventional and ribbon synapses, respectively, and that ubMunc13-2 is the only Munc13 isoform in mature photoreceptor ribbon synapses. Strikingly, the genetic deletion of ubMunc13-2 has little effect on synaptic signaling by photoreceptor ribbon synapses and does not prevent membrane attachment of synaptic vesicles at the photoreceptor ribbon synaptic site. Thus, photoreceptor ribbon synapses and conventional synapses differ fundamentally with regard to their dependence on SV priming proteins of the Munc13 family. Their function is only moderately affected by Munc13 loss, which leads to slight perturbations of signal integration in the retina.
- Subjects :
- Amacrine Cells physiology
Animals
Cloning, Molecular
DNA, Complementary biosynthesis
DNA, Complementary genetics
Electroretinography
Exocytosis genetics
Exocytosis physiology
Fluorescent Antibody Technique
Immunohistochemistry
Intracellular Signaling Peptides and Proteins genetics
Isomerism
Mice
Mice, Knockout
Microscopy, Electron
Nerve Tissue Proteins genetics
RNA biosynthesis
RNA genetics
Retina cytology
Retina physiology
Retina ultrastructure
Synapses ultrastructure
Synaptic Vesicles drug effects
Synaptic Vesicles ultrastructure
Transcription, Genetic
Intracellular Signaling Peptides and Proteins physiology
Nerve Tissue Proteins physiology
Synapses physiology
Synaptic Vesicles physiology
Subjects
Details
- Language :
- English
- ISSN :
- 1529-2401
- Volume :
- 32
- Issue :
- 23
- Database :
- MEDLINE
- Journal :
- The Journal of neuroscience : the official journal of the Society for Neuroscience
- Publication Type :
- Academic Journal
- Accession number :
- 22674279
- Full Text :
- https://doi.org/10.1523/JNEUROSCI.4240-11.2012