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
More filters
Journal ArticleDOI
Astrogliosis: An integral player in the pathogenesis of Alzheimer's disease.
TL;DR: This review considers the molecular and functional changes occurring during astrogliosis in Alzheimer's disease, and proposes that astrocytes are key players in the development of dementia.
Journal ArticleDOI
Astrocyte Heterogeneity: Impact to Brain Aging and Disease.
TL;DR: The molecules and mechanisms triggered by astrocyte to control synapse formation in different brain regions are focused on, as well as their likely impact for the brain function during aging and neural diseases.
Journal ArticleDOI
Astrocytes, neurons, synapses: a tripartite view on cortical circuit development.
TL;DR: A combined overview of the developmental processes of synapse and circuit formation in the rodent cortex is provided, emphasizing the timeline of both neuronal and astrocytic development and maturation.
Journal ArticleDOI
Multifunctional role of astrocytes as gatekeepers of neuronal energy supply.
TL;DR: The role of astrocytes as a hub for neurometabolic and neurovascular coupling mechanisms is a critical underpinning for therapeutic development in a broad range of neurodegenerative disorders characterized by chronic generalized brain ischemia and brain microvascular dysfunction.
Journal ArticleDOI
In vivo Stimulus-Induced Vasodilation Occurs without IP3 Receptor Activation and May Precede Astrocytic Calcium Increase
Krystal Nizar,Hana Uhlirova,Peifang Tian,Payam A. Saisan,Qun Cheng,Lidia Reznichenko,Kimberly L. Weldy,Tyler Steed,Vishnu B. Sridhar,Christopher L. MacDonald,Jianxia Cui,Sergey L. Gratiy,Sava Sakadzic,David A. Boas,Thomas Ibsa Beka,Gaute T. Einevoll,Ju Chen,Eliezer Masliah,Anders M. Dale,Gabriel A. Silva,Anna Devor +20 more
TL;DR: The results in wild-type (WT) mice indicate that in vivo onset of astrocytic calcium increase in response to sensory stimulus could be considerably delayed relative to the simultaneously measured onset of arteriolar dilation, suggesting astroCytes may not play a role in the initiation of blood flow response, at least not via calcium-dependent mechanisms.
References
More filters
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
Control of synapse number by glia.
TL;DR: It is shown that few synapses form in the absence of glial cells and that the fewsynapses that do form are functionally immature, and that CNS synapse number can be profoundly regulated by nonneuronal signals.
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.