title: Memory Formation Shaped by Astroglia.
abstract: Astrocytes, the most heterogeneous glial cells in the central nervous system (CNS), execute a multitude of homeostatic functions and contribute to memory formation. Consolidation of synaptic and systemic memory is a prolonged process and hours are required to form long-term memory. In the past, neurons or their parts have been considered to be the exclusive cellular sites of these processes, however, it has now become evident that astrocytes provide an important and essential contribution to memory formation. Astrocytes participate in the morphological remodeling associated with synaptic plasticity, an energy-demanding process that requires mobilization of glycogen, which, in the CNS, is almost exclusively stored in astrocytes. Synaptic remodeling also involves bidirectional astroglial-neuronal communication supported by astroglial receptors and release of gliosignaling molecules. Astroglia exhibit cytoplasmic excitability that engages second messengers, such as Ca(2+), for phasic, and cyclic adenosine monophosphate (cAMP), for tonic signal coordination with neuronal processes. The detection of signals by astrocytes and the release of gliosignaling molecules, in particular by vesicle-based mechanisms, occurs with a significant delay after stimulation, orders of magnitude longer than that present in stimulus-secretion coupling in neurons. These particular arrangements position astrocytes as integrators ideally tuned to support time-dependent memory formation.
authors.affiliation: Laboratory of Neuroendocrinology and Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana Ljubljana, Slovenia ; Celica Biomedical Ljubljana, Slovenia.
authors.forename: Robert
authors.initials: R
authors.lastname: Zorec
authors.affiliation: Laboratory of Neuroendocrinology and Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana Ljubljana, Slovenia.
authors.forename: Anemari
authors.initials: A
authors.lastname: Horvat
authors.affiliation: Laboratory of Neuroendocrinology and Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana Ljubljana, Slovenia ; Celica Biomedical Ljubljana, Slovenia.
authors.forename: Nina
authors.initials: N
authors.lastname: Vardjan
authors.affiliation: Laboratory of Neuroendocrinology and Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana Ljubljana, Slovenia ; Celica Biomedical Ljubljana, Slovenia ; Faculty of Life Sciences, University of Manchester Manchester, UK ; Achucarro Center for Neuroscience, Ikerbasque, Basque Foundation for Science Bilbao, Spain ; Department of Neurosciences, University of the Basque Country Leioa, Spain ; University of Nizhny Novgorod Nizhny Novgorod, Russia.
authors.forename: Alexei
authors.initials: A
authors.lastname: Verkhratsky
keywords: astroglia; memory; metabolism; shape; signaling