Journal ArticleDOI
Astrocyte signaling controls spike timing–dependent depression at neocortical synapses
Rogier Min,Thomas Nevian +1 more
TLDR
Astrocyte stimulation coincident with afferent activity resulted in long-term depression, indicating that astrocyte activation is sufficient for the induction of synaptic depression, and describes the retrograde signaling cascade underlying neocortical t-LTD.Abstract:
Endocannabinoid mediated spike timing-dependent depression (t-LTD) is crucially involved in the development of the sensory neocortex. t-LTD at excitatory synapses in the developing rat barrel cortex requires cannabinoid CB(1) receptor (CB(1)R) activation, as well as activation of NMDA receptors located on the presynaptic terminal, but the exact signaling cascade leading to t-LTD remains unclear. We found that astrocytes are critically involved in t-LTD. Astrocytes gradually increased their Ca(2+) signaling specifically during the induction of t-LTD in a CB(1)R-dependent manner. In this way, astrocytes might act as a memory buffer for previous coincident neuronal activity. Following activation, astrocytes released glutamate, which activated presynaptic NMDA receptors to induce t-LTD. Astrocyte stimulation coincident with afferent activity resulted in long-term depression, indicating that astrocyte activation is sufficient for the induction of synaptic depression. Taken together, our findings describe the retrograde signaling cascade underlying neocortical t-LTD. The critical involvement of astrocytes in this process highlights their importance for experience-dependent sensory remodeling.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
Endocannabinoid Signaling and Synaptic Function
TL;DR: New advances in synaptic endocannabinoid signaling in the mammalian brain are focused on and the emerging picture not only reinforcesendocannabinoids as potent regulators of synaptic function but also reveals that endoc cannabinoidoid signaling is mechanistically more complex and diverse than originally thought.
Journal ArticleDOI
The spike-timing dependence of plasticity.
TL;DR: A broader view of plasticity is summarized, including the forms and cellular mechanisms for the spike-timing dependence of Plasticity, and, the evidence that spike timing is an important determinant of plasticsity in vivo is summarized.
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.
References
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Tetanus and botulinum-B neurotoxins block neurotransmitter release by proteolytic cleavage of synaptobrevin
Giampietro Schiavo,Fabio Benfenati,Bernard Poulain,Ornella Rossetto,Patrizia Polverino de Laureto,Bibhuti R. DasGupta,Cesare Montecucco +6 more
TL;DR: The results indicate that tetanus and botulinum B neurotoxins block neurotransmitter release by cleaving synaptobrevin-2, a protein that, on the basis of the results, seems to play a key part in neurotransmitterRelease.
Journal ArticleDOI
Glutamate-mediated astrocyte-neuron signalling.
Vladimir Parpura,Trent A. Basarsky,Fang Liu,Ksenija Jeftinija,Srdija Jeftinija,Philip G. Haydon +5 more
TL;DR: Astrocytes regulate neuronal calcium levels through the calcium-dependent release of glutamate, and an NMDA (N-methyl-d-aspartate) receptor-mediated increase in neuronal calcium is demonstrated.
Journal ArticleDOI
Astrocyte Control of Synaptic Transmission and Neurovascular Coupling
TL;DR: The application of subcellular imaging of Ca2+ signaling to astrocytes now provides functional data to support this structural notion that both excitatory and inhibitory signals provided by the same glial cell act in concert to regulate neuronal function.