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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Journal ArticleDOI
The role of astrocytes in behaviors related to emotion and motivation
Eiji Shigetomi,Schuichi Koizumi +1 more
TL;DR: A review of recent progress on the role of astrocytes in behaviors related to emotion and motivation can be found in this paper , where the main focus has been on G-protein coupled receptors.
DissertationDOI
Neuroinflammation and the role of glia: relevance for neurodegenerative and neurosupportive roles
TL;DR: The results suggest that astrocytes react to inflammatory stimuli by transiently rearranging their mitochondria, a process that involves the autophagic machinery.
Posted ContentDOI
Optogenetic activation of Gq signaling in astrocytes yields stimulation-specific effects on basal hippocampal synaptic excitation and inhibition
Connor D. Courtney,Courtney Sobieski,Charu Ramakrishnan,Robbie J. Ingram,Natalia M. Wojnowski,Richard A. DeFazio,Karl Deisseroth,Catherine A. Christian-Hinman +7 more
TL;DR: The AAV8-GFAP-Optoα1AR-eYFP (Opto1AR) as mentioned in this paper was proposed to activate the Gq-mediated intracellular cascade via light-sensitive α1-adrenergic receptors.
Posted ContentDOI
Simulation of calcium signaling in fine astrocytic processes: effect of spatial properties on spontaneous activity
Denizot Audrey,Arizono Misa,Arizono Misa,Nägerl U. Valentin,Nägerl U. Valentin,Soula Hédi,Berry Hugues +6 more
TL;DR: This model is the first model suited to investigate calcium dynamics in fine astrocytic processes and to propose plausible mechanisms responsible for their variability, and is both spatially explicit and particle-based.
Journal ArticleDOI
Astrocyte arborization enhances Ca2+ but not cAMP signaling plasticity.
Samo Pirnat,Mićo Božić,Dorian Dolanc,Anemari Horvat,Petra Tavčar,Nina Vardjan,Alexei Verkhratsky,Alexei Verkhratsky,Robert Zorec,Matjaž Stenovec +9 more
TL;DR: In this article, the authors used cultured astrocytes to investigate at subcellular level basic cell processes under controlled environmental conditions, and found altered vesicle dynamics associated with increased resting [Ca2+ ]i and increased sub-cellular heterogeneity in [Ca 2+ ] i, whereas [cAMP]i subcellule dynamics remained stable in both cultures, indicating that cAMP signaling is less prone to plastic remodeling than Ca2+ signaling.
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
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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.