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
Animal models of transcranial direct current stimulation: Methods and mechanisms
Mark P. Jackson,Asif Rahman,Belen Lafon,Greg Kronberg,Doris Ling,Lucas C. Parra,Marom Bikson +6 more
TL;DR: It is discussed how this strategy, itself based on classic animal studies, cannot account for the complexity of normal and pathological brain function, and how recent studies have already indicated more sophisticated approaches are necessary.
Journal ArticleDOI
Optogenetic astrocyte activation modulates response selectivity of visual cortex neurons in vivo
TL;DR: It is reported that selective photostimulation of astrocytes with channelrhodopsin-2 in primary visual cortex enhances both excitatory and inhibitory synaptic transmission, through the activation of type 1a metabotropic glutamate receptors.
Journal ArticleDOI
Probing the complexities of astrocyte calcium signaling
TL;DR: Progress in the past few years, fueled by methodological advances, has reignited interest in astrocyte Ca(2+) signaling for brain function and dysfunction.
Journal ArticleDOI
Diversity and Specificity of Astrocyte-neuron Communication.
Caitlin A. Durkee,Alfonso Araque +1 more
TL;DR: Diversity and complexity of astrocyte-synapse interactions greatly enhance the degrees of freedom of the neural circuits and the consequent computational power of the Neural systems.
Book ChapterDOI
Gliotransmission and the Tripartite Synapse
TL;DR: By releasing gliotransmitters in millisecond time scale with a specific vesicular apparatus, astrocytes can integrate and process synaptic information and control or modulate synaptic transmission and plasticity.
References
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Journal ArticleDOI
Tripartite synapses: astrocytes process and control synaptic information
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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.