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
Gliotransmitters Travel in Time and Space
Alfonso Araque,Giorgio Carmignoto,Philip G. Haydon,Stéphane H. R. Oliet,Richard Robitaille,Andrea Volterra +5 more
TL;DR: It is proposed that astrocytes mainly signal through high-affinity slowly desensitizing receptors to modulate neurons and perform integration in spatiotemporal domains complementary to those of neurons.
Journal ArticleDOI
Physiology of astroglia
TL;DR: Astrocytes are tightly integrated into neural networks and act within the context of neural tissue; astrocytes control homeostasis of the CNS at all levels of organization from molecular to the whole organ.
Journal ArticleDOI
Diversity of astrocyte functions and phenotypes in neural circuits
TL;DR: New insights herald the concept that astrocytes represent a diverse population of genetically tractable cells that mediate neural circuit–specific roles in health and disease.
Journal ArticleDOI
Astrocyte Calcium Signaling: The Third Wave
Narges Bazargani,David Attwell +1 more
TL;DR: The discovery that transient elevations of calcium concentration occur in astrocytes, and release 'gliotransmitters' which act on neurons and vascular smooth muscle, led to the idea that astroCytes are powerful regulators of neuronal spiking, synaptic plasticity and brain blood flow.
Supporting Online Material for Astrocytes Potentiate Transmitter Release at Single Hippocampal Synapses
Gertrudis Perea,Alfonso Araque +1 more
TL;DR: Results indicate that astrocytes are actively involved in the transfer and storage of synaptic information and mGluR-mediated but N-methyl-d-aspartate receptor–independent plasticity is observed.
References
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Visualization of localized store-operated calcium entry in mouse astrocytes. Close proximity to the endoplasmic reticulum
TL;DR: It is shown that store‐operated Ca2+ entry (SOCE) in primary cultured mouse cortical astrocytes occurs at plasma membrane–ER junctions, and TRPC‐encoded SOCs are confined to the PM microdomains adjacent to the underlying ‘junctional’ ER.
Journal ArticleDOI
GABA uptake-dependent Ca2+ signaling in developing olfactory bulb astrocytes
Michael Doengi,Daniela Hirnet,Philippe Coulon,Hans-Christian Pape,Joachim W. Deitmer,Christian Lohr +5 more
TL;DR: The results suggest that GABA transporters not only remove GABA from the extracellular space, but may also contribute to intracellular signaling and astrocyte function, such as control of blood flow.
Journal ArticleDOI
Developmental changes in membrane properties and postsynaptic currents of granule cells in rat dentate gyrus
TL;DR: It is concluded that PSCs evoked by medial perforant path stimulation produce a fast inward current comparable with respect to latency to peak, latency to onset, and 10-90% rise time in neurons of all maturities held at -80 mV, and GABA current decreased with increasing cell maturity.
Book
The tripartite synapse: glia in synaptic transmission
TL;DR: The concept of glial cells as active elements of the synapse and the nervous circuitry is introduced, the experimental evidence supporting this is described and a revised view of brain activity based on this integrated network of interactive neurons and glia is suggested.
Journal ArticleDOI
Immunogold Detection of L-glutamate and D-serine in Small Synaptic-Like Microvesicles in Adult Hippocampal Astrocytes
Linda H. Bergersen,Cecilie Morland,Lasse Ormel,Johanne Egge Rinholm,Max Larsson,J.F.H. Wold,Åsmund T. Røe,A. Stranna,Mirko Santello,David Bouvier,O.P. Ottersen,Andrea Volterra,Vidar Gundersen,Vidar Gundersen +13 more
TL;DR: It is shown by immunogold cytochemistry of the adult hippocampus that glutamate and D-serine accumulate in synaptic-like microvesicles (SLMVs) in the perisynaptic processes of astrocytes.