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Neuro-Signals 2008
Topics: Animals; Computer Simulation; Humans; Models, Neurological; Nerve Net; Nervous System Physiological Phenomena; Signal Transduction; Synaptic Transmission
PubMed: 18635942
DOI: 10.1159/000123036 -
The European Journal of Neuroscience Dec 2022Chemical synapses are tiny and overcrowded environments, deeply embedded inside brain tissue and enriched with thousands of protein species. Many efforts have been... (Review)
Review
Chemical synapses are tiny and overcrowded environments, deeply embedded inside brain tissue and enriched with thousands of protein species. Many efforts have been devoted to developing custom approaches for evaluating and modifying synaptic activity. Most of these methods are based on the engineering of one or more synaptic protein scaffolds used to target active moieties to the synaptic compartment or to manipulate synaptic functioning. In this review, we summarize the most recent methodological advances and provide a description of the involved proteins as well as the operation principle. Furthermore, we highlight their advantages and limitations in relation to studies of synaptic transmission in vitro and in vivo. Concerning the labelling methods, the most important challenge is how to extend the available approaches to the in vivo setting. On the other hand, for those methods that allow manipulation of synaptic function, this limit has been overcome using optogenetic approaches that can be more easily applied to the living brain. Finally, future applications of these methods to neuroscience, as well as new potential routes for development, are discussed.
Topics: Synapses; Neurons; Synaptic Transmission; Optogenetics; Brain
PubMed: 36239030
DOI: 10.1111/ejn.15848 -
Journal of Neurophysiology May 2011The synaptic vesicle population in a nerve terminal is traditionally divided into subpopulations according to physiological criteria; the readily releasable pool (RRP),... (Comparative Study)
Comparative Study
The synaptic vesicle population in a nerve terminal is traditionally divided into subpopulations according to physiological criteria; the readily releasable pool (RRP), the recycling pool, and the reserve pool. It is recognized that the RRP subserves synaptic transmission evoked by low-frequency neural activity and that the recycling and reserve populations are called on to supply vesicles as neural activity increases. Here we investigated the contribution of nonmuscle myosin II (NMMII) to synaptic transmission with emphasis on the role a motor protein could play in the supply of vesicles. We used Drosophila genetics to manipulate NMMII and assessed synaptic transmission at the larval neuromuscular junction. We observed a positive correlation between synaptic strength at low-frequency stimulation and NMMII expression: reducing NMMII reduced the evoked response, while increasing NMMII increased the evoked response. Further, we found that NMMII contributed to the spontaneous release of vesicles differentially from evoked release, suggesting differential contribution to these two release mechanisms. By measuring synaptic responses under conditions of differing external calcium concentration in saline, we found that NMMII is important for normal synaptic transmission under high-frequency stimulation. This research identifies diverse functions for NMMII in synaptic transmission and suggests that this motor protein is an active contributor to the physiology of synaptic vesicle recruitment.
Topics: Animals; Animals, Genetically Modified; Drosophila Proteins; Drosophila melanogaster; Neuromuscular Junction; Neuronal Plasticity; Nonmuscle Myosin Type IIB; Synaptic Potentials; Synaptic Transmission; Synaptic Vesicles
PubMed: 21325687
DOI: 10.1152/jn.00718.2010 -
Trends in Neurosciences Jun 2018Today, we understand peptide transmitters to be signaling molecules that modulate neural activity. However, in 1982 little was known about neuropeptides and their role... (Review)
Review
Today, we understand peptide transmitters to be signaling molecules that modulate neural activity. However, in 1982 little was known about neuropeptides and their role in neural communication. The influential 1982 paper by Jan and Jan reported definitive evidence that a presynaptically released neuropeptide evokes postsynaptic responses in an identified cholinergic synapse, thereby fueling a new era in neuroscience.
Topics: Animals; Humans; Neuropeptides; Presynaptic Terminals; Synaptic Transmission
PubMed: 29801523
DOI: 10.1016/j.tins.2018.03.013 -
Neuron Feb 2022Spatiotemporal control of brain activity by optogenetics has emerged as an essential tool to study brain function. For silencing brain activity, optogenetic probes, such...
Spatiotemporal control of brain activity by optogenetics has emerged as an essential tool to study brain function. For silencing brain activity, optogenetic probes, such as halorhodopsin and archaerhodopsin, inhibit transmitter release indirectly by hyperpolarizing membrane potentials. However, these probes cause an undesirable ionic imbalance and rebound spikes. Moreover, they are not applicable to use in non-excitable glial cells. Here we engineered Opto-vTrap, a light-inducible and reversible inhibition system to temporarily trap the transmitter-containing vesicles from exocytotic release. Light activation of Opto-vTrap caused full vesicle clusterization and complete inhibition of exocytosis within 1 min, which recovered within 30 min after light off. We found a significant reduction in synaptic and gliotransmission upon activation of Opto-vTrap in acute brain slices. Opto-vTrap significantly inhibited hippocampus-dependent memory retrieval with full recovery within an hour. We propose Opto-vTrap as a next-generation optogenetic silencer to control brain activity and behavior with minimal confounding effects.
Topics: Brain; Exocytosis; Hippocampus; Optogenetics; Synaptic Transmission
PubMed: 34852235
DOI: 10.1016/j.neuron.2021.11.003 -
Neuron Glia Biology Aug 2010There is a growing body of evidence suggesting a functional relationship between Ca2+ signals generated in astroglia and the functioning of nearby excitatory synapses.... (Review)
Review
There is a growing body of evidence suggesting a functional relationship between Ca2+ signals generated in astroglia and the functioning of nearby excitatory synapses. Interference with endogenous Ca2+ homeostasis inside individual astrocytes has been shown to affect synaptic transmission and its use-dependent changes. However, establishing the causal link between source-specific, physiologically relevant intracellular Ca2+ signals, the astrocytic release machinery and the consequent effects on synaptic transmission has proved difficult. Improved methods of Ca2+ monitoring in situ will be essential for resolving the ambiguity in understanding the underlying Ca2+ signalling cascades.
Topics: Animals; Astrocytes; Calcium Signaling; Humans; Neuronal Plasticity; Synaptic Transmission
PubMed: 20939938
DOI: 10.1017/S1740925X10000153 -
Neuroscience Letters Jun 2023Caffeic acid is a polyphenolic compound present in a vast array of dietary components. We previously showed that caffeic acid reduces the burden of brain ischemia...
Caffeic acid is a polyphenolic compound present in a vast array of dietary components. We previously showed that caffeic acid reduces the burden of brain ischemia joining evidence by others that it can attenuate different brain diseases. However, it is unknown if caffeic acid affects information processing in neuronal networks. Thus, we now used electrophysiological recordings in mouse hippocampal slices to test if caffeic acid directly affected synaptic transmission, plasticity and dysfunction caused by oxygen-glucose deprivation (OGD), an in vitro ischemia model. Caffeic acid (1-10 μM) was devoid of effect on synaptic transmission and paired-pulse facilitation in Schaffer collaterals-CA1 pyramidal synapses. Also, the magnitude of either hippocampal long-term potentiation (LTP) or the subsequent depotentiation were not significantly modified by 10 μM caffeic acid. However, caffeic acid (10 μM) increased the recovery of synaptic transmission upon re-oxygenation following 7 min of OGD. Furthermore, caffeic acid (10 μM) also recovered plasticity after OGD, as heralded by the increased magnitude of LTP after exposure. These findings show that caffeic acid does not directly affect synaptic transmission and plasticity but can indirectly affect other cellular targets to correct synaptic dysfunction. Unraveling the molecular mechanisms of action of caffeic acid may allow the design of hitherto unrecognized novel neuroprotective strategies.
Topics: Mice; Animals; Hippocampus; Synaptic Transmission; Long-Term Potentiation; Ischemia; Neuronal Plasticity
PubMed: 37156440
DOI: 10.1016/j.neulet.2023.137292 -
Current Biology : CB Oct 1995The kinetics of different steps in synaptic-vesicle recycling, including exocytosis, internalization and repriming, have recently been estimated in various types of... (Review)
Review
The kinetics of different steps in synaptic-vesicle recycling, including exocytosis, internalization and repriming, have recently been estimated in various types of living cell.
Topics: Animals; Synaptic Transmission; Synaptic Vesicles; Time Factors
PubMed: 8548276
DOI: 10.1016/s0960-9822(95)00220-x -
Philosophical Transactions of the Royal... Aug 2010Numerous evidence demonstrates that astrocytes, a type of glial cell, are integral functional elements of the synapses, responding to neuronal activity and regulating... (Review)
Review
Numerous evidence demonstrates that astrocytes, a type of glial cell, are integral functional elements of the synapses, responding to neuronal activity and regulating synaptic transmission and plasticity. Consequently, they are actively involved in the processing, transfer and storage of information by the nervous system, which challenges the accepted paradigm that brain function results exclusively from neuronal network activity, and suggests that nervous system function actually arises from the activity of neuron-glia networks. Most of our knowledge of the properties and physiological consequences of the bidirectional communication between astrocytes and neurons resides at cellular and molecular levels. In contrast, much less is known at higher level of complexity, i.e. networks of cells, and the actual impact of astrocytes in the neuronal network function remains largely unexplored. In the present article, we summarize the current evidence that supports the notion that astrocytes are integral components of nervous system networks and we discuss some functional properties of intercellular signalling in neuron-glia networks.
Topics: Animals; Astrocytes; Brain; Cell Communication; Nerve Net; Neurons; Synaptic Transmission
PubMed: 20603358
DOI: 10.1098/rstb.2009.0313 -
Medecine Sciences : M/S 2022
Topics: Dopaminergic Neurons; Humans; Synapses; Synaptic Transmission
PubMed: 36094225
DOI: 10.1051/medsci/2022088