title: Astrocytes in endocannabinoid signalling.
abstract: Astrocytes are emerging as integral functional components of synapses, responding to synaptically released neurotransmitters and regulating synaptic transmission and plasticity. Thus, they functionally interact with neurons establishing tripartite synapses: a functional concept that refers to the existence of communication between astrocytes and neurons and its crucial role in synaptic function. Here, we discuss recent evidence showing that astrocytes are involved in the endocannabinoid (ECB) system, responding to exogenous cannabinoids as well as ECBs through activation of type 1 cannabinoid receptors, which increase intracellular calcium and stimulate the release of glutamate that modulates synaptic transmission and plasticity. We also discuss the consequences of ECB signalling in tripartite synapses on the astrocyte-mediated regulation of synaptic function, which reveal novel properties of synaptic regulation by ECBs, such as the spatially controlled dual effect on synaptic strength and the lateral potentiation of synaptic efficacy. Finally, we discuss the potential implications of ECB signalling for astrocytes in brain pathology and animal behaviour.
authors.affiliation: Instituto Cajal, CSIC, Madrid 28002, Spain.
authors.forename: Marta
authors.initials: M
authors.lastname: Navarrete
authors.affiliation: Instituto Cajal, CSIC, Madrid 28002, Spain.
authors.forename: Adolfo
authors.initials: A
authors.lastname: Díez
authors.affiliation: Instituto Cajal, CSIC, Madrid 28002, Spain Department of Neuroscience, University of Minnesota, Minneapolis, MN 55455, USA araque@umn.edu.
authors.forename: Alfonso
authors.initials: A
authors.lastname: Araque
mesh_terms: D001253:Astrocytes / Q000378:metabolism / Q000502:physiology*; D063388:Endocannabinoids / Q000378:metabolism*; D006801:Humans; D008959:Models, Neurological; D009473:Neuronal Plasticity / Q000502:physiology; D018377:Neurotransmitter Agents / Q000378:metabolism*; D043882:Receptors, Cannabinoid / Q000378:metabolism*; D015398:Signal Transduction / Q000502:physiology*; D013569:Synapses / Q000378:metabolism / Q000502:physiology*; D009435:Synaptic Transmission / Q000502:physiology
chemical_list: D063388:Endocannabinoids; D018377:Neurotransmitter Agents; D043882:Receptors, Cannabinoid
keywords: astrocytes; communication; endocannabinoids; gliotransmitter release; neuron–glia; tripartite synapses