The actin-spectrin submembrane scaffold restricts endocytosis along proximal axons

bioRxiv (Cold Spring Harbor Laboratory), Год журнала: 2023, Номер unknown

Опубликована: Дек. 19, 2023

Abstract Neuronal clathrin-mediated endocytosis has unique features in compartments such as dendrites and presynaptic boutons, but how membrane extracellular components are internalized along the axon shaft remains poorly known. Here we focused on clathrin-coated structures initial segment (AIS), their relationship to periodic actin-spectrin scaffold that lines axonal plasma membrane. Super-resolution optical microscopy, platinum replica electron correlative combination cultured hippocampal neurons reveal AIS, pits form bare patches, ∼300 nm circular areas devoid of spectrin mesh lined by actin filaments termed “clearings”. In fibroblasts proximal neurons, depletion drug-induced disorganization increase pit formation. However, presence at AIS is not directly linked actual endocytosis: using cargo uptake live-cell imaging experiments, find most long-lived immobile within clearings. Direct perturbation well elevated neuronal activity could induce downstream clathrin formation, showing clearings responsible for regulated AIS.

Язык: Английский

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Deciphering the nanoscale architecture of presynaptic actin using a micropatterned presynapse-on-glass model

bioRxiv (Cold Spring Harbor Laboratory), Год журнала: 2024, Номер unknown

Опубликована: Сен. 5, 2024

Abstract Chemical synapses are fundamental units for the transmission of information throughout nervous system. The cyto-skeleton allows to build, maintain and transform both pre- postsynaptic contacts, yet its organization role unique synaptic nanostructures still poorly understood. Here we present a presynapse-on-glass model where presynaptic specializations robustly induced along axons cultured neurons by micropatterned dots neuroligin, allowing controlled orientation easy optical visualization functional presynapses. We demonstrate relevance usefulness this study actin architecture, showing that majority presynapses enriched in actin, with enrichment being correlated higher cycling activity. confirm our previous results on bead-induced identifying same distinct with-in presynapses: corrals, rails mesh. Furthermore, leverage model, visualizing arrangement these structures relative active zone nanoclusters using multicolor 3D Single Molecule Localization Microscopy (SMLM), sub-diffractive localization exocytic events correlative live-cell SMLM approach.

Язык: Английский

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The synaptic vesicle cluster as a controller of pre‐ and postsynaptic structure and function

The Journal of Physiology, Год журнала: 2024, Номер unknown

Опубликована: Окт. 5, 2024

Abstract The synaptic vesicle cluster (SVC) is an essential component of chemical synapses, which provides neurotransmitter‐loaded vesicles during activity, at the same time as also controlling local concentrations numerous exo‐ and endocytosis cofactors. In addition, SVC hosts molecules that participate in other aspects function, from cytoskeletal components to adhesion proteins, affects location function organelles such mitochondria endoplasmic reticulum. We argue here these features extend functional involvement synapse formation, signalling plasticity, well stabilization metabolism. propose changes size coalesce with postsynaptic compartment, supporting interplay between pre‐ dynamics. Thereby, could be seen ‘all‐in‐one’ regulator structure should investigated more detail, reveal molecular mechanisms control heterogeneity. image

Язык: Английский

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Recently recycled synaptic vesicles use multi-cytoskeletal transport and differential presynaptic capture probability to establish a retrograde net flux during ISVE in central neurons

Frontiers in Cell and Developmental Biology, Год журнала: 2023, Номер 11

Опубликована: Ноя. 6, 2023

Presynapses locally recycle synaptic vesicles to efficiently communicate information. During use and recycling, proteins on the surface of break down become less efficient. In order maintain efficient presynaptic function accommodate protein breakdown, new are regularly produced in soma trafficked locations where they replace older protein-carrying vesicles. Maintaining a balance is thus essential for maintenance plasticity. While production turnover have been extensively studied, it still unclear how back recycling balance. present study, we combination fluorescence microscopy, hippocampal cell cultures, computational analyses determine mechanisms that mediate vesicle trafficking soma. We show vesicles, which recently undergone exocytosis, can differentially utilize either microtubule or actin cytoskeleton networks. axonally traveling with higher speeds network likely be captured by presynapses, while slower more presynapses. also retrograde-driven neighboring presynapse than anterograde-driven loss bound molecular motor myosin V mechanism differentiates whether will Finally, theoretical framework our experimentally observed retrograde bias maintains previously rates from

Язык: Английский

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Non-muscle myosin II regulates presynaptic actin assemblies and neuronal mechanobiology

bioRxiv (Cold Spring Harbor Laboratory), Год журнала: 2023, Номер unknown

Опубликована: Ноя. 13, 2023

Neuromuscular junctions (NMJs) are evolutionarily ancient, specialized contacts between neurons and muscles. Axons NMJs must endure mechanical strain through a lifetime of muscle contraction, making them vulnerable to aging neurodegenerative conditions. However, cellular strategies for mitigating this stress remain unknown. In study, we used Drosophila larval investigate the role actin myosin (actomyosin)-mediated contractility in generating responding forces at neuron-muscle interface. We identified new long-lived, low-turnover presynaptic core traversing NMJ, which partly co-localizes with non-muscle II (NMII). Neuronal RNAi NMII induced disorganization core, suggesting that structure might have contractile properties. Interestingly, neuronal also decreased levels postsynaptic proximal neurons, actomyosin rearrangements propagate their effects transsynaptically. observed reduced Integrin upon knockdown, indicating disruption triggers Integrin-mediated connections surrounding tissue. summary, our study identifies previously uncharacterized subpopulation upholds continuum, transmits signals adjacent tissue, collaborates receptors govern mechanobiology neuromuscular junction.

Язык: Английский

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Rho GTPase signaling and mDia facilitate endocytosis via presynaptic actin

eLife, Год журнала: 2024, Номер 12

Опубликована: Март 19, 2024

Neurotransmission at synapses is mediated by the fusion and subsequent endocytosis of synaptic vesicle membranes. Actin has been suggested to be required for presynaptic but mechanisms that control actin polymerization its mode action within nerve terminals remain poorly understood. We combine optical recordings membrane dynamics ultrastructural analysis with genetic pharmacological manipulations demonstrate controlled regulatory diaphanous-related formins mDia1/3 Rho family GTPase signaling in mouse hippocampal neurons. show impaired assembly near absence reduced RhoA activity partly compensated hyperactivation Rac1. Inhibition Rac1 further aggravates elicited loss mDia1/3. Our data suggest interdependent mDia1/3-Rho pathways cooperatively act facilitate controlling F-actin.

Язык: Английский

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Single-Molecule-Resolution Approaches in Synaptic Biology

The Journal of Physical Chemistry B, Год журнала: 2024, Номер 128(13), С. 3061 - 3068

Опубликована: Март 21, 2024

Synapses between neurons are the primary loci for information transfer and storage in brain. An individual neuron, alone, can make over 10000 synaptic contacts. It is, however, not easy to investigate what goes on locally within a synapse because many compartments only few hundred nanometers wide size─close diffraction limit of light. To observe biomolecular machinery processes synapses, situ single-molecule techniques emerging as powerful tools. Guided by important biological questions, this Perspective will highlight recent advances using these obtain measurements molecules three aspects: cell-biological architecture, neurotransmitter receptors. These showcase increasing importance single-molecule-resolution accessing subcellular biophysical related

Язык: Английский

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Myosin VI controls localization of Golgi satellites at active presynaptic boutons

bioRxiv (Cold Spring Harbor Laboratory), Год журнала: 2024, Номер unknown

Опубликована: Май 9, 2024

Abstract Neurons, as long-living non-dividing cells with complex morphology, depend on highly elaborate secretory trafficking system which ensures the constant delivery, removal and recycling of proteins membranes. Previously, we have shown that simplified Golgi-related structures called Golgi satellites (GS), distinct from somatic complex, are present in dendrites primary hippocampal neurons involved glycosylation local forward membrane proteins. However, whether GS also targeted to axons principal not been explored. Here, investigate subcellular distribution adult discover mobile stationary along entire axonal length, extending distal tips growth cone. Live imaging experiments revealed neuronal firing modulates switch between long range transport mediated by kinesin dynein stalling. We found frequently pause or stop at pre-synaptic sites activity-dependent manner. This behavior depends actin cytoskeleton actin-based motor protein myosin VI. Overall, our study demonstrates activity can dynamically regulate positioning axon, shedding light intricate mechanisms underlying organelle neurons. Significance statement Our unveils presence dynamic specialized organelles implicated trafficking, within throughout including cone regions. transported bidirectionally their preferential pausing presynaptic is regulated firing. boutons relies VI protein. work elucidates how distribution, fundamental

Язык: Английский

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Actomyosin-mediated inhibition of synaptic vesicle release under CB1R activation

Translational Psychiatry, Год журнала: 2024, Номер 14(1)

Опубликована: Авг. 21, 2024

Long-term synaptic plasticity is critical for adaptive function of the brain, but presynaptic mechanisms functional remain poorly understood. Here, we show that changes in efficacy induced by activation cannabinoid type-1 receptor (CB

Язык: Английский

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Single-vesicle imaging reveals actin-dependent spatial restriction of vesicles at the active zone, essential for sustained transmission

Proceedings of the National Academy of Sciences, Год журнала: 2024, Номер 121(43)

Опубликована: Окт. 15, 2024

Synaptic-vesicle (SV) recruitment is thought to maintain reliable neurotransmitter release during high-frequency signaling. However, the mechanism underlying SV reloading for sustained neurotransmission at central synapses remains unknown. To elucidate this, we performed direct observations of and mobility a single-vesicle level near plasma membrane in cerebellar mossy fiber terminals using total internal reflection fluorescence microscopy, together with simultaneous recordings fusion by capacitance measurements. We found that actin disruption abolished rapid reduced release. In contrast, induction polymerization stabilization did not affect vesicle release, suggesting presence filaments, rather than dynamics, was required recruitment. Single-particle tracking experiments quantum dot-labeled vesicles, which allows nanoscale resolution mobility, revealed caused vesicles diffuse more rapidly. Hidden Markov modeling Bayesian inference SVs had two diffusion states under normal conditions: free-diffusing trapped. After filament, tended have only state. F-actin staining showed filaments were localized outside active zones (AZs) surrounded some trajectories. Perturbation possibly through interference biomolecular condensates, also suggested restricted state determined rate propose confined AZ achieve efficient followed priming synaptic transmission.

Язык: Английский

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