Journal ArticleDOI
Local Ca2+ detection and modulation of synaptic release by astrocytes
Maria Amalia Di Castro,Julien Chuquet,Nicolas Liaudet,Khaleel Bhaukaurally,Mirko Santello,David Bouvier,Pascale Tiret,Andrea Volterra +7 more
TLDR
Evidence is provided that astrocytes are integrated in local synaptic functioning in adult brain through GTP- and inositol-1,4,5-trisphosphate–dependent signaling and is relevant for basal synaptic function.Abstract:
Astrocytes communicate with synapses by means of intracellular calcium ([Ca(2+)](i)) elevations, but local calcium dynamics in astrocytic processes have never been thoroughly investigated. By taking advantage of high-resolution two-photon microscopy, we identify the characteristics of local astrocyte calcium activity in the adult mouse hippocampus. Astrocytic processes showed intense activity, triggered by physiological transmission at neighboring synapses. They encoded synchronous synaptic events generated by sparse action potentials into robust regional (∼12 μm) [Ca(2+)](i) elevations. Unexpectedly, they also sensed spontaneous synaptic events, producing highly confined (∼4 μm), fast (millisecond-scale) miniature Ca(2+) responses. This Ca(2+) activity in astrocytic processes is generated through GTP- and inositol-1,4,5-trisphosphate-dependent signaling and is relevant for basal synaptic function. Thus, buffering astrocyte [Ca(2+)](i) or blocking a receptor mediating local astrocyte Ca(2+) signals decreased synaptic transmission reliability in minimal stimulation experiments. These data provide direct evidence that astrocytes are integrated in local synaptic functioning in adult brain.read more
Citations
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Posted ContentDOI
Astrocyte nanoscale morphology controls Ca2+ signals at tripartite synapses
TL;DR: In this article, the causal relationship between branchlet morphology and spatio-temporal profile of Ca2+ signals was investigated using 3D reticular branchlet geometries alternating between large nodes and thinner cellular compartments.
Journal ArticleDOI
Targeting CDK5 in Astrocytes Promotes Calcium Homeostasis Under Excitotoxic Conditions.
Luisa Fernanda Toro-Fernández,Luisa Fernanda Toro-Fernández,Juan Camilo Zuluaga-Monares,Juan Camilo Zuluaga-Monares,Ana María Saldarriaga-Cartagena,Ana María Saldarriaga-Cartagena,Gloria Patricia Cardona-Gómez,Rafael Andrés Posada-Duque,Rafael Andrés Posada-Duque +8 more
TL;DR: In this paper, CDK5-targeted astrocytes were transplanted in CA3 and remained at the injection site without proliferation, regulated calcium in the CA1 hippocampal region after excitotoxicity by glutamate, improving synapsin and PSD95 clustering.
Journal ArticleDOI
Disintegration of the Astroglial Domain Organization May Underlie the Loss of Reality Comprehension in Schizophrenia: A Hypothetical Model
TL;DR: In this article, a pathophysiological model of the loss of reality comprehension in schizophrenia is proposed, based on a formalism, and it is hypothesized that astroglial domains exert an information-categorizing function which becomes progressively lost in the schizophrenic process, caused by functional and structural disintegration of the brain.
Dissertation
Simulating calcium signaling in fine astrocytic processes
TL;DR: The spatially-extended stochastic model that this work has developed is a prerequisite for understanding neuron-astrocyte communication and its influence on brain function and contributes to a better understanding of astrocytes Ca2+ signals.
Journal ArticleDOI
Glial heterogeneity: the increasing complexity of the brain
TL;DR: Both imaging techniques take thus advantage of the strategic positions of glial cells which enable them to power neurons and to maintain long-range connections, highlighting the prominent role of neuroglia in neuronal performance.
References
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Journal ArticleDOI
Tripartite synapses: astrocytes process and control synaptic information
TL;DR: There is an emerging view, which is reviewed herein, in which brain function actually arises from the coordinated activity of a network comprising both neurons and glia, rather than the classically accepted paradigm that brain function results exclusively from neuronal activity.
Journal ArticleDOI
Control of synapse number by glia.
TL;DR: It is shown that few synapses form in the absence of glial cells and that the fewsynapses that do form are functionally immature, and that CNS synapse number can be profoundly regulated by nonneuronal signals.
Journal ArticleDOI
Long-term potentiation depends on release of d -serine from astrocytes
Christian Henneberger,Thomas Papouin,Thomas Papouin,Stéphane H. R. Oliet,Stéphane H. R. Oliet,Dmitri A. Rusakov +5 more
TL;DR: It is demonstrated that Ca2+-dependent release of d-serine from an astrocyte controls NMDAR-dependent plasticity in many thousands of excitatory synapses nearby.
Journal ArticleDOI
Definition of the Readily Releasable Pool of Vesicles at Hippocampal Synapses
TL;DR: It is found that hypertonic solutions do not act through changes in intracellular calcium, which means that the synaptic release probability depends on the size of the readily releasable pool.
Journal ArticleDOI
Neuronal Synchrony Mediated by Astrocytic Glutamate through Activation of Extrasynaptic NMDA Receptors
TL;DR: The results reveal a distinct mechanism for neuronal excitation and synchrony and highlight a functional link between astrocytic glutamate and extrasynaptic NMDA receptors.