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
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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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Journal ArticleDOI
Excitatory synaptic activity is associated with a rapid structural plasticity of inhibitory synapses on hippocampal CA1 pyramidal cells.
TL;DR: Data reveal a rapid activity-related restructuring of somatic inhibitory synapses characterized by an enlargement and increased complexity of inhibitory PSDs, providing a new mechanism for a quick adjustment of the excitatory-inhibitory balance.
Journal ArticleDOI
NMDA Receptor Currents Suppress Synapse Formation on Sprouting Axons In Vivo
TL;DR: The results suggest that during early development, NMDAR currents predominantly destabilize nascent synapses, but as the neuropil matures, competition for synaptic space suppresses axon sprouting and synapse formation regardless of N MDAR function.