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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Book ChapterDOI
The Astrocyte-Neuron Interface: An Overview on Molecular and Cellular Dynamics Controlling Formation and Maintenance of the Tripartite Synapse.
Uzma Hasan,Sandeep Singh +1 more
TL;DR: In this chapter, the methodologies used in deciphering the mechanisms of dynamic interplay between astrocytes and neurons are briefly overviewed.
Posted ContentDOI
Morphological profile determines the frequency of spontaneous calcium events in astrocytic processes
TL;DR: The results suggest that the morphological profile of the astrocytic processes is responsible for tuning of the Ca2+ event frequency, which can be directly translated into changes in ast rocytic Ca2-dependent signaling.
Journal ArticleDOI
Regulation of neurovascular coupling in autoimmunity to water and ion channels.
Peter Jukkola,Chen Gu +1 more
TL;DR: Four types of channel proteins that are expressed in astrocytes are highlighted, regarding their structures, biophysical properties, expression and distribution patterns, and related diseases including autoimmune disorders.
Journal ArticleDOI
Assessment of astrocytes as a mediator of memory and learning in rodents
Sonam Akther,Hajime Hirase +1 more
TL;DR: A review of the role of astrocytes in brain plasticity in rodents can be found in this paper, where the roles of neurotransmitters and neuromodulators are considered to be comparable to those in humans.
Journal ArticleDOI
Synaptic neuron-astrocyte communication is supported by an order of magnitude analysis of inositol tris-phosphate diffusion at the nanoscale in a model of peri-synaptic astrocyte projection.
TL;DR: A idealized model of a PAP (PAPm) is idealized to perform an order of magnitude analysis of IP3 diffusion using a transient mass diffusion model and indicates that Ca2+ stores position in PAP’s does not limit SN-AmcIP3.
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.