Subtle modulation of ongoing calcium dynamics in astrocytic microdomains by sensory inputs
| Autor: | Sakiko Ujita, Ryota Nakayama, Norio Matsuki, Akiko Asada, Shin Ishii, Yuji Ikegaya, Shigeyuki Oba |
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| Rok vydání: | 2015 |
| Předmět: |
Physiology
chemistry.chemical_element Sensory system Calcium orientation selectivity Bioinformatics endfoot Imaging data chemistry.chemical_compound Visual cortex medicine.anatomical_structure chemistry In vivo Calcium dynamics Physiology (medical) map medicine Tetrodotoxin visual cortex Astrocyte Neuroscience Original Research |
| Zdroj: | Physiological Reports |
| ISSN: | 2051-817X |
| DOI: | 10.14814/phy2.12454 |
| Popis: | Astrocytes communicate with neurons through their processes. In vitro experiments have demonstrated that astrocytic processes exhibit calcium activity both spontaneously and in response to external stimuli; however, it has not been fully determined whether and how astrocytic subcellular domains respond to sensory input in vivo. We visualized the calcium signals in astrocytes in the primary visual cortex of awake, head‐fixed mice. Bias‐free analyses of two‐photon imaging data revealed that calcium activity prevailed in astrocytic subcellular domains, was coordinated with variable spot‐like patterns, and was dominantly spontaneous. Indeed, visual stimuli did not affect the frequency of calcium domain activity, but it increased the domain size, whereas tetrodotoxin reduced the sizes of spontaneous calcium domains and abolished their visual responses. The "evoked" domain activity exhibited no apparent orientation tuning and was distributed unevenly within the cell, constituting multiple active hotspots that were often also recruited in spontaneous activity. The hotspots existed dominantly in the somata and endfeet of astrocytes. Thus, the patterns of astrocytic calcium dynamics are intrinsically constrained and are subject to minor but significant modulation by sensory input. |
| Databáze: | OpenAIRE |
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