scholarly journals Decision letter: RIM-BP2 primes synaptic vesicles via recruitment of Munc13-1 at hippocampal mossy fiber synapses

2018 ◽  
Author(s):  
Craig Curtis Garner
Keyword(s):  
Synaptic Vesicles ◽  
Mossy Fiber

scholarly journals Author response: RIM-BP2 primes synaptic vesicles via recruitment of Munc13-1 at hippocampal mossy fiber synapses

2019 ◽  
Author(s):  
Marisa M Brockmann ◽  
Marta Maglione ◽  
Claudia G Willmes ◽  
Alexander Stumpf ◽  
Boris A Bouazza ◽  
...  
Keyword(s):  
Synaptic Vesicles ◽  
Mossy Fiber ◽  
Author Response

A comparative morphometric study of synaptic vesicles and other organelles in mossy fiber endings of the pigeon and the rat

1978 ◽  
Vol 100 (4) ◽  
pp. 471-477 ◽  
Author(s):  
M.M. Paula-Barbosa ◽  
M.A. Sobrinho-Simões ◽  
R. Faria
Keyword(s):  
Synaptic Vesicles ◽  
Mossy Fiber ◽  
Morphometric Study

scholarly journals RIM-BP2 primes synaptic vesicles via recruitment of Munc13-1 at hippocampal mossy fiber synapses

eLife ◽  
2019 ◽  
Vol 8 ◽  
Author(s):  
Marisa M Brockmann ◽  
Marta Maglione ◽  
Claudia G Willmes ◽  
Alexander Stumpf ◽  
Boris A Bouazza ◽  
...  
Keyword(s):  
Active Zone ◽  
Neurotransmitter Release ◽  
Synaptic Vesicles ◽  
Mossy Fiber ◽  
Substantial Impact ◽  
Vesicle Docking ◽  
Vesicular Release ◽  
Anatomical Properties ◽  
Presynaptic Protein ◽  
Determinant Factor

All synapses require fusion-competent vesicles and coordinated Ca2+-secretion coupling for neurotransmission, yet functional and anatomical properties are diverse across different synapse types. We show that the presynaptic protein RIM-BP2 has diversified functions in neurotransmitter release at different central murine synapses and thus contributes to synaptic diversity. At hippocampal pyramidal CA3-CA1 synapses, RIM-BP2 loss has a mild effect on neurotransmitter release, by only regulating Ca2+-secretion coupling. However, at hippocampal mossy fiber synapses, RIM-BP2 has a substantial impact on neurotransmitter release by promoting vesicle docking/priming and vesicular release probability via stabilization of Munc13-1 at the active zone. We suggest that differences in the active zone organization may dictate the role a protein plays in synaptic transmission and that differences in active zone architecture is a major determinant factor in the functional diversity of synapses.

scholarly journals Calcium dependence of neurotransmitter release at a high fidelity synapse

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Abdelmoneim Eshra ◽  
Hartmut Schmidt ◽  
Jens Eilers ◽  
Stefan Hallermann
Keyword(s):  
High Frequency ◽  
Neurotransmitter Release ◽  
Synaptic Vesicles ◽  
Mossy Fiber ◽  
High Fidelity ◽  
Technical Challenge ◽  
Fundamental Parameters ◽  
High Affinity ◽  
Vesicle Pools ◽  
Intracellular Ca

The Ca2+-dependence of the priming, fusion, and replenishment of synaptic vesicles are fundamental parameters controlling neurotransmitter release and synaptic plasticity. Despite intense efforts, these important steps in the synaptic vesicles’ cycle remain poorly understood due to the technical challenge in disentangling vesicle priming, fusion, and replenishment. Here, we investigated the Ca2+-sensitivity of these steps at mossy fiber synapses in the rodent cerebellum, which are characterized by fast vesicle replenishment mediating high-frequency signaling. We found that the basal free Ca2+ concentration (<200 nM) critically controls action potential-evoked release, indicating a high-affinity Ca2+ sensor for vesicle priming. Ca2+ uncaging experiments revealed a surprisingly shallow and non-saturating relationship between release rate and intracellular Ca2+ concentration up to 50 μM. The rate of vesicle replenishment during sustained elevated intracellular Ca2+ concentration exhibited little Ca2+-dependence. Finally, quantitative mechanistic release schemes with five Ca2+ binding steps incorporating rapid vesicle replenishment via parallel or sequential vesicle pools could explain our data. We thus show that co-existing high- and low-affinity Ca2+ sensors mediate priming, fusion, and replenishment of synaptic vesicles at a high-fidelity synapse.

scholarly journals Immunogold electron microscopic demonstration of glutamate and GABA in normal and deafferented cerebellar cortex: correlation between transmitter content and synaptic vesicle size.

1990 ◽  
Vol 38 (12) ◽  
pp. 1767-1777 ◽  
Author(s):  
J Hámori ◽  
J Takács ◽  
P Petrusz
Keyword(s):  
Cerebellar Cortex ◽  
Synaptic Vesicles ◽  
Mossy Fiber ◽  
Average Diameter ◽  
Cerebellar Nuclei ◽  
Convincing Evidence ◽  
Gamma Aminobutyric Acid ◽  
Electron Microscopic ◽  
Size And Shape ◽  
Axon Terminals

Selective labeling of mossy fiber terminals and parallel fibers was obtained in rat cerebellar cortex by a glutamate antibody produced and characterized by Hepler et al. The high-resolution electron microscopic immunogold demonstration of this amino acid offered the possibility of determining the size and shape of synaptic vesicles in glutamate-positive mossy endings. Mossy terminals that stained with the glutamate antibody formed two distinct populations, one with spherical synaptic vesicles with an average diameter of 34.0 nm (more than 90% of all mossy fiber endings) and one with pleomorphic and smaller synaptic vesicles which had an average diameter of 28.5 nm. We present experimental evidence that the mossy terminals with large round vesicles are of extracerebellar origin, whereas those with small pleomorphic synaptic vesicles are endings of nucleocortical fibers. The presence of two distinct classes of gamma-aminobutyric acid (GABA)-containing axon terminals within cerebellar glomeruli has also been demonstrated; those originating from the cerebellar nuclei contain large (36.2 nm) synaptic vesicles, whereas the majority of GABA-stained axon terminals that are of local (cortical) origin contain small (29.1 nm) synaptic vesicles. It therefore appears that, at least in the case of glutamate and GABA, morphological characterization of the axon terminals based on the size and shape of synaptic vesicles is not a reliable indicator of their functional nature (i.e., whether they are excitatory or inhibitory); convincing evidence for the identity of the transmitter can be obtained only by electron microscopic immunostaining procedures. Our results also suggest the existence of both inhibitory and excitatory feedback from cerebellar nuclei to cerebellar cortex.

scholarly journals Direct imaging of rapid tethering of synaptic vesicles accompanying exocytosis at a fast central synapse

2020 ◽  
Vol 117 (25) ◽  
pp. 14493-14502 ◽  
Author(s):  
Takafumi Miki ◽  
Mitsuharu Midorikawa ◽  
Takeshi Sakaba
Keyword(s):  
Synaptic Vesicles ◽  
Total Internal Reflection ◽  
Time Course ◽  
Mossy Fiber ◽  
High Rate ◽  
Presynaptic Membrane ◽  
Sustained Activity ◽  
Central Synapse ◽  
Tightly Coupled ◽  
Rapid Information Processing

A high rate of synaptic vesicle (SV) release is required at cerebellar mossy fiber terminals for rapid information processing. As the number of release sites is limited, fast SV reloading is necessary to achieve sustained release. However, rapid reloading has not been observed directly. Here, we visualize SV movements near presynaptic membrane using total internal reflection fluorescence (TIRF) microscopy. Upon stimulation, SVs appeared in the TIRF-field and became tethered to the presynaptic membrane with unexpectedly rapid time course, almost as fast as SVs disappeared due to release. However, such stimulus-induced tethering was abolished by inhibiting exocytosis, suggesting that the tethering is tightly coupled to preceding exocytosis. The newly tethered vesicles became fusion competent not immediately but only 300 ms to 400 ms after tethering. Together with model simulations, we propose that rapid tethering leads to an immediate filling of vacated spaces and release sites within <100 nm of the active zone by SVs, which serve as precursors of readily releasable vesicles, thereby shortening delays during sustained activity.

scholarly journals Kinetics of Releasable Synaptic Vesicles and Their Plastic Changes at Hippocampal Mossy Fiber Synapses

Neuron ◽  
2017 ◽  
Vol 96 (5) ◽  
pp. 1033-1040.e3 ◽  
Author(s):  
Mitsuharu Midorikawa ◽  
Takeshi Sakaba
Keyword(s):  
Synaptic Vesicles ◽  
Mossy Fiber ◽  
Plastic Changes ◽  
Kinetics Of

scholarly journals Calcium dependence of neurotransmitter release at a high fidelity synapse

2021 ◽  
Author(s):  
Abdelmoneim Eshra ◽  
Hartmut Schmidt ◽  
Jens Eilers ◽  
Stefan Hallermann
Keyword(s):  
Synaptic Plasticity ◽  
Release Rate ◽  
High Frequency ◽  
Neurotransmitter Release ◽  
Synaptic Vesicles ◽  
Mossy Fiber ◽  
High Fidelity ◽  
Fundamental Parameters ◽  
High Affinity ◽  
Vesicle Pools

The Ca2+-dependence of the recruitment, priming, and fusion of synaptic vesicles are fundamental parameters controlling neurotransmitter release and synaptic plasticity. Despite intense efforts, these important steps in the synaptic vesicles cycle remain poorly understood because disentangling recruitment, priming, and fusion of vesicles is technically challenging. Here, we investigated the Ca2+-sensitivity of these steps at cerebellar mossy fiber synapses, which are characterized by fast vesicle recruitment mediating high-frequency signaling. We found that the basal free Ca2+ concentration (<200 nM) critically controls action potential-evoked release, indicating a high-affinity Ca2+ sensor for vesicle priming. Ca2+ uncaging experiments revealed a surprisingly shallow and non-saturating relationship between release rate and intracellular Ca2+ concentration up to 50 μM. Sustained vesicle recruitment was Ca2+-independent. Finally, quantitative mechanistic release schemes with five Ca2+ binding steps incorporating rapid vesicle recruitment via parallel or sequential vesicle pools could explain our data. We thus show that co-existing high and low-affinity Ca2+ sensors mediate recruitment, priming, and fusion of synaptic vesicles at a high-fidelity synapse.

scholarly journals RIM-BP2 primes synaptic vesicles via recruitment of Munc13-1 at hippocampal mossy fiber synapses

2018 ◽  
Author(s):  
Marisa M Brockmann ◽  
Marta Maglione ◽  
Claudia G Willmes ◽  
Alexander Stumpf ◽  
A Boris Bouazza ◽  
...  
Keyword(s):  
Neurotransmitter Release ◽  
Synaptic Vesicles ◽  
Spatial Organization ◽  
Mossy Fiber ◽  
Strong Impact ◽  
Wild Type ◽  
Vesicle Docking ◽  
Presynaptic Protein ◽  
Determinant Factor ◽  
High Diversity

SummaryAll synapses require fusion-competent vesicles and coordinated Ca2+-secretion coupling for neurotransmission, yet functional and anatomical properties show a high diversity across different synapse types. We show here that the presynaptic protein RIM-BP2 has diversified functions in neurotransmitter release at different central mammalian synapses and thus contributes to synaptic diversity. At hippocampal pyramidal CA3-CA1 synapses, RIM-BP2 loss has a mild effect on neurotransmitter release, by only regulating Ca2+-secretion coupling. However, at hippocampal mossy fiber synapses RIM-BP2 has a strong impact on neurotransmitter release by promoting vesicle docking/priming via recruitment of Munc13-1. In wild type mossy fiber synapses, the distance between RIM-BP2 clusters and Munc13-1 clusters is larger than in hippocampal pyramidal CA3-CA1 synapses, suggesting that spatial organization may dictate the role a protein plays in synaptic transmission and that differences in active zone architecture is a major determinant factor in the functional diversity of synapses.

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