scholarly journals A Conditional Glutamatergic Synaptic Vesicle Marker for Drosophila

2022 ◽  
Author(s):  
Sarah J Certel ◽  
Evelyne Ruchti ◽  
Brian D McCabe ◽  
R Steven Stowers
Keyword(s):  
Nervous System ◽  
Synaptic Vesicles ◽  
Neural Circuit ◽  
Glutamate Release ◽  
Nervous System Development ◽  
Central Complex ◽  
Excitatory Neurotransmitter ◽  
Glutamatergic Neurons ◽  
Brain Functions ◽  
Conditional Expression

Abstract Glutamate is a principal neurotransmitter used extensively by the nervous systems of all vertebrate and invertebrate animals. It is primarily an excitatory neurotransmitter that has been implicated in nervous system development as well as a myriad of brain functions from the simple transmission of information between neurons to more complex aspects of nervous system function including synaptic plasticity, learning, and memory. Identification of glutamatergic neurons and their sites of glutamate release are thus essential for understanding the mechanisms of neural circuit function and how information is processed to generate behavior. Here we describe and characterize smFLAG-vGlut, a conditional marker of glutamatergic synaptic vesicles for the Drosophila model system. smFLAG-vGlut is validated for functionality, conditional expression, and specificity for glutamatergic neurons and synaptic vesicles. The utility of smFLAG-vGlut is demonstrated by glutamatergic neurotransmitter phenotyping of 26 different central complex neuron types of which nine were established to be glutamatergic. This illumination of glutamate neurotransmitter usage will enhance the modeling of central complex neural circuitry and thereby our understanding of information processing by this region of the fly brain. The use of smFLAG for glutamatergic neurotransmitter phenotyping and identification of glutamate release sites can be extended to any Drosophila neuron(s) represented by a binary transcription system driver.

scholarly journals Proteolysis and neurogenesis modulated by LNR domain proteins explosion support male differentiation in the crustacean Oithona nana

2019 ◽  
Author(s):  
Kevin Sugier ◽  
Romuald Laso-Jadart ◽  
Soheib Kerbache ◽  
Jos Kafer ◽  
Majda Arif ◽  
...  
Keyword(s):  
Nervous System ◽  
Amino Acid ◽  
Developmental Stages ◽  
System Development ◽  
Nervous System Development ◽  
Numerical Density ◽  
Female Ratio ◽  
Excitatory Neurotransmitter ◽  
Protein Protein Interaction ◽  
Sex Determination System

AbstractCopepods are the most numerous animals and play an essential role in the marine trophic web and biogeochemical cycles. The genus Oithona is described as having the highest numerical density, as the most cosmopolite copepod and iteroparous. The Oithona male paradox obliges it to alternate feeding (immobile) and mating (mobile) phases. As the molecular basis of this trade-off is unknown, we investigated this sexual dimorphism at the molecular level by integrating genomic, transcriptomic and protein-protein interaction analyses.While a ZW sex-determination system was predicted in O. nana, a fifteen-year time-series in the Toulon Little Bay showed a biased sex ratio toward females (male / female ratio < 0.15±0.11) highlighting a higher mortality in male. Here, the transcriptomic analysis of the five different developmental stages showed enrichment of Lin12-Notch Repeat (LNR) domains-containing proteins coding genes (LDPGs) in male transcripts. The male also showed enrichment in transcripts involved in proteolysis, nervous system development, synapse assembly and functioning and also amino acid conversion to glutamate. Moreover, several male down-regulated genes were involved in the increase of food uptake and digestion. The formation of LDP complexes was detected by yeast two-hybrid, with interactions involving proteases, extracellular matrix proteins and neurogenesis related proteins.Together, these results suggest that the O. nana male hypermotility is sustained by LDP-modulated proteolysis allowing the releases and conversions of amino acid into the excitatory neurotransmitter glutamate. This process could permit new axons and dendrites formation suggesting a sexual nervous system dimorphism. This could support the hypothesis of a sacrificial behaviour in males at the metabolic level.

scholarly journals Counting the Number of Glutamate Molecules in Single Synaptic Vesicles

2019 ◽  
Author(s):  
Yuanmo Wang ◽  
Hoda fathali ◽  
devesh mishra ◽  
Thomas Olsson ◽  
Jacqueline Keighron ◽  
...  
Keyword(s):  
Synaptic Vesicle ◽  
Synaptic Vesicles ◽  
High Speed ◽  
Glutamate Release ◽  
Dependent Manner ◽  
Excitatory Neurotransmitter ◽  
Quantitative Measurements ◽  
Sensor Technique ◽  
Drug Treatments ◽  
Analytical Tools

<div><p>Analytical tools for direct quantitative measurements of glutamate, the principal excitatory neurotransmitter in brain, are lacking. Here, we introduce a new enzyme-based amperometric sensor technique for direct counting of the number of glutamate molecules stored inside single synaptic vesicles. An ultra-fast enzyme-based glutamate sensor is placed into a solution of isolated synaptic vesicles, which stochastically rupture at the sensor surface in a potential dependent manner by applying a constant negative potential. High-speed (10 kHz) amperometry is used to record sub-millisecond current spikes, which represent glutamate release from single vesicles that burst open. Glutamate quantification is achieved by a calibration curve that is based on measurements of glutamate release from vesicles pre-filled with various concentrations of glutamate. Our measurements show that a single synaptic vesicle encapsulates about 8000 glutamate molecules, which is comparable to the measured exocytotic quantal glutamate release in the nucleus accumbens of mouse brain tissue. Hence, this new methodology introduces the means to quantify ultra-small amounts of glutamate and to study synaptic vesicle physiology, pathogenesis and drug treatments for neuronal disorders where glutamate is involved.</p></div>

scholarly journals Mechanisms of Glutamate Transport

2013 ◽  
Vol 93 (4) ◽  
pp. 1621-1657 ◽  
Author(s):  
Robert J. Vandenberg ◽  
Renae M. Ryan
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Glutamate Transporter ◽  
Glutamate Transporters ◽  
Structural Basis ◽  
Broad Perspective ◽  
Excitatory Neurotransmitter ◽  
Brain Functions ◽  
Transporter Family ◽  
The Central Nervous System

l-Glutamate is the predominant excitatory neurotransmitter in the mammalian central nervous system and plays important roles in a wide variety of brain functions, but it is also a key player in the pathogenesis of many neurological disorders. The control of glutamate concentrations is critical to the normal functioning of the central nervous system, and in this review we discuss how glutamate transporters regulate glutamate concentrations to maintain dynamic signaling mechanisms between neurons. In 2004, the crystal structure of a prokaryotic homolog of the mammalian glutamate transporter family of proteins was crystallized and its structure determined. This has paved the way for a better understanding of the structural basis for glutamate transporter function. In this review we provide a broad perspective of this field of research, but focus primarily on the more recent studies with a particular emphasis on how our understanding of the structure of glutamate transporters has generated new insights.

scholarly journals Multiplex imaging of quantal glutamate release and presynaptic Ca2+ at multiple synapses in situ

2018 ◽  
Author(s):  
Thomas P. Jensen ◽  
Kaiyu Zheng ◽  
Nicholas Cole ◽  
Jonathan S. Marvin ◽  
Loren L. Looger ◽  
...  
Keyword(s):  
Neural Circuit ◽  
Glutamate Release ◽  
Loose Coupling ◽  
Excitatory Neurotransmitter ◽  
Presynaptic Function ◽  
Brain Circuits ◽  
Presynaptic Boutons ◽  
Central Synapses ◽  
Nanomolar Range

AbstractInformation processing by brain circuits depends on Ca2+-dependent, stochastic release of the excitatory neurotransmitter glutamate. Optical glutamate sensors have enabled detection of evoked and spontaneous synaptic discharges. However, monitoring presynaptic function and its underpinning machinery in situ requires simultaneous readout of quantal glutamate release and nanomolar presynaptic Ca2+. Here, we find that the fluorescence lifetime of the red-shifted Ca2+ indicator Cal-590 is Ca2+-sensitive in the nanomolar range, and employ it in combination with green glutamate sensors to relate quantal neurotransmission to presynaptic Ca2+ kinetics. Imaging of multiple synapses in an identified neural circuit reveals that fluctuations both in spike-evoked Ca2+ transients and in resting presynaptic Ca2+ can affect release efficacy. At the sub-microscopic level within individual presynaptic boutons, we detected no consistent co-localisation of presynaptic Ca2+ entry and glutamate release sites, suggesting loose coupling between the two. The present approach broadens qualitatively our horizon in understanding release machinery of central synapses.

scholarly journals m6A Modification in Mammalian Nervous System Development, Functions, Disorders, and Injuries

2021 ◽  
Vol 9 ◽  
Author(s):  
Jun Yu ◽  
Yuanchu She ◽  
Sheng-Jian Ji
Keyword(s):  
Nervous System ◽  
Neuronal Development ◽  
System Development ◽  
Nervous System Development ◽  
Mammalian Brain ◽  
Biological Processes ◽  
Brain Functions ◽  
Mrna Metabolism ◽  
Dynamic Modification ◽  
Underlying Mechanisms

N6-methyladenosine (m6A) modification, as the most prevalent internal modification on mRNA, has been implicated in many biological processes through regulating mRNA metabolism. Given that m6A modification is highly enriched in the mammalian brain, this dynamic modification provides a crucial new layer of epitranscriptomic regulation of the nervous system. Here, in this review, we summarize the recent progress on studies of m6A modification in the mammalian nervous system ranging from neuronal development to basic and advanced brain functions. We also highlight the detailed underlying mechanisms in each process mediated by m6A writers, erasers, and readers. Besides, the involvement of dysregulated m6A modification in neurological disorders and injuries is discussed as well.

The Na+/H+ Exchanger Nhe1 Modulates Network Excitability via GABA Release

2018 ◽  
Vol 29 (10) ◽  
pp. 4263-4276 ◽  
Author(s):  
Hartmut T Bocker ◽  
Theresa Heinrich ◽  
Lutz Liebmann ◽  
J Christopher Hennings ◽  
Eric Seemann ◽  
...  
Keyword(s):  
Synaptic Vesicles ◽  
Neuronal Excitability ◽  
Ph Dependence ◽  
Gaba Release ◽  
Epileptic Activity ◽  
Inhibitory Interneurons ◽  
Gabaergic Interneurons ◽  
Glutamatergic Neurons ◽  
Brain Functions ◽  
Ph Dependent

Abstract Brain functions are extremely sensitive to pH changes because of the pH-dependence of proteins involved in neuronal excitability and synaptic transmission. Here, we show that the Na+/H+ exchanger Nhe1, which uses the Na+ gradient to extrude H+, is expressed at both inhibitory and excitatory presynapses. We disrupted Nhe1 specifically in mice either in Emx1-positive glutamatergic neurons or in parvalbumin-positive cells, mainly GABAergic interneurons. While Nhe1 disruption in excitatory neurons had no effect on overall network excitability, mice with disruption of Nhe1 in parvalbumin-positive neurons displayed epileptic activity. From our electrophysiological analyses in the CA1 of the hippocampus, we conclude that the disruption in parvalbumin-positive neurons impairs the release of GABA-loaded vesicles, but increases the size of GABA quanta. The latter is most likely an indirect pH-dependent effect, as Nhe1 was not expressed in purified synaptic vesicles itself. Conclusively, our data provide first evidence that Nhe1 affects network excitability via modulation of inhibitory interneurons.

scholarly journals The role of astrocyte‐mediated plasticity in neural circuit development and function

2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Nelson A. Perez-Catalan ◽  
Chris Q. Doe ◽  
Sarah D. Ackerman
Keyword(s):  
Nervous System ◽  
Neural Plasticity ◽  
Neural Circuit ◽  
System Development ◽  
Critical Role ◽  
Nervous System Development ◽  
Functional Changes ◽  
Sensory Evoked ◽  
And Function

AbstractNeuronal networks are capable of undergoing rapid structural and functional changes called plasticity, which are essential for shaping circuit function during nervous system development. These changes range from short-term modifications on the order of milliseconds, to long-term rearrangement of neural architecture that could last for the lifetime of the organism. Neural plasticity is most prominent during development, yet also plays a critical role during memory formation, behavior, and disease. Therefore, it is essential to define and characterize the mechanisms underlying the onset, duration, and form of plasticity. Astrocytes, the most numerous glial cell type in the human nervous system, are integral elements of synapses and are components of a glial network that can coordinate neural activity at a circuit-wide level. Moreover, their arrival to the CNS during late embryogenesis correlates to the onset of sensory-evoked activity, making them an interesting target for circuit plasticity studies. Technological advancements in the last decade have uncovered astrocytes as prominent regulators of circuit assembly and function. Here, we provide a brief historical perspective on our understanding of astrocytes in the nervous system, and review the latest advances on the role of astroglia in regulating circuit plasticity and function during nervous system development and homeostasis.

scholarly journals PRL-1 is required for neuroprotection against olfactory CO2 stimulation in Drosophila

2018 ◽  
Author(s):  
Pengfei Guo ◽  
Xiao Xu ◽  
Fang Wang ◽  
Xin Yuan ◽  
Yinqi Tu ◽  
...  
Keyword(s):  
Nervous System ◽  
Olfactory Receptor ◽  
Neural Circuits ◽  
Neural Circuit ◽  
Mutant Phenotype ◽  
Brain Disorder ◽  
Conditional Expression ◽  
Magnesium Transporter ◽  
Obvious Consequence ◽  
Phosphatase Of Regenerating Liver

AbstractThe Mammalian phosphatase of regenerating liver (PRL) family is primarily recognized for its oncogenic properties. Here we found that in Drosophila, loss of prl-1 resulted in CO2-induced brain disorder presented as irreversible wing hold up with enhancement of Ca2+ responses at the neuron synaptic terminals. Overexpression of Prl-1 in the nervous system could rescue the mutant phenotype. We show that Prl-1 is particularly expressed in CO2-responsive neural circuit and the higher brain centers. Ablation of the CO2 olfactory receptor, Gr21a, suppressed the mutant phenotype, suggesting that CO2 acts as a neuropathological substrate in absence of Prl-1. Further studies found that the wing hold up is an obvious consequence upon knockdown of Uex, a magnesium transporter, which directly interacts with Prl-1. Conditional expression of Uex in the nervous system could rescue the phenotype of prl-1 mutants. We demonstrate that Uex acts genetically downstream of Prl-1. Our findings provide important insights into mechanisms of Prl-1 protection against olfactory CO2 stimulation induced brain disorder at the level of detailed neural circuits and functional molecular connections.

scholarly journals Counting the Number of Glutamate Molecules in Single Synaptic Vesicles

2019 ◽  
Author(s):  
Yuanmo Wang ◽  
Hoda fathali ◽  
devesh mishra ◽  
Thomas Olsson ◽  
Jacqueline Keighron ◽  
...  
Keyword(s):  
Synaptic Vesicle ◽  
Synaptic Vesicles ◽  
High Speed ◽  
Glutamate Release ◽  
Dependent Manner ◽  
Excitatory Neurotransmitter ◽  
Quantitative Measurements ◽  
Sensor Technique ◽  
Drug Treatments ◽  
Analytical Tools

<div><p>Analytical tools for direct quantitative measurements of glutamate, the principal excitatory neurotransmitter in brain, are lacking. Here, we introduce a new enzyme-based amperometric sensor technique for direct counting of the number of glutamate molecules stored inside single synaptic vesicles. An ultra-fast enzyme-based glutamate sensor is placed into a solution of isolated synaptic vesicles, which stochastically rupture at the sensor surface in a potential dependent manner by applying a constant negative potential. High-speed (10 kHz) amperometry is used to record sub-millisecond current spikes, which represent glutamate release from single vesicles that burst open. Glutamate quantification is achieved by a calibration curve that is based on measurements of glutamate release from vesicles pre-filled with various concentrations of glutamate. Our measurements show that a single synaptic vesicle encapsulates about 8000 glutamate molecules, which is comparable to the measured exocytotic quantal glutamate release in the nucleus accumbens of mouse brain tissue. Hence, this new methodology introduces the means to quantify ultra-small amounts of glutamate and to study synaptic vesicle physiology, pathogenesis and drug treatments for neuronal disorders where glutamate is involved.</p></div>

scholarly journals Genetic Transsynaptic Techniques for Mapping Neural Circuits in Drosophila

2021 ◽  
Vol 15 ◽  
Author(s):  
Lina Ni
Keyword(s):  
Nervous System ◽  
Neural Circuits ◽  
Neural Circuit ◽  
Specific Function ◽  
Crucial Importance ◽  
High Reproducibility ◽  
Brain Functions ◽  
Structural Framework ◽  
Brain Circuit ◽  
Chemical Synapses

A neural circuit is composed of a population of neurons that are interconnected by synapses and carry out a specific function when activated. It is the structural framework for all brain functions. Its impairments often cause diseases in the nervous system. To understand computations and functions in a brain circuit, it is of crucial importance to identify how neurons in this circuit are connected. Genetic transsynaptic techniques provide opportunities to efficiently answer this question. These techniques label synapses or across synapses to unbiasedly label synaptic partners. They allow for mapping neural circuits with high reproducibility and throughput, as well as provide genetic access to synaptically connected neurons that enables visualization and manipulation of these neurons simultaneously. This review focuses on three recently developed Drosophila genetic transsynaptic tools for detecting chemical synapses, highlights their advantages and potential pitfalls, and discusses the future development needs of these techniques.

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