Ultrastructural view of astrocyte arborization, astrocyte-astrocyte and astrocyte-synapse contacts, intracellular vesicle-like structures, and mitochondrial network

The complexity of astrocyte morphology and syncytial coupling through gap junctions are crucial for astrocyte function in the brain. However, the ultrastructural details of astrocyte arborization and interactions between neighboring astrocytes remain unknown. While a prevailing view is that synapses...

Full description

Saved in:

Bibliographic Details
Published in:	Progress in neurobiology Vol. 213; p. 102264
Main Authors:	Aten, Sydney, Kiyoshi, Conrad M., Arzola, Emily P., Patterson, Jeremy A., Taylor, Anne T., Du, Yixing, Guiher, Ally M., Philip, Merna, Camacho, Elizabeth Gerviacio, Mediratta, Devin, Collins, Kelsey, Boni, Kirsten, Garcia, Silvana A., Kumar, Rahul, Drake, Aiden N., Hegazi, Ahlam, Trank, Lindsey, Benson, Emily, Kidd, Grahame, Terman, David, Zhou, Min
Format:	Journal Article
Language:	English
Published:	England Elsevier Ltd 01-06-2022
Subjects:	Aldh1l1-eGFP Astrocyte network Astrocytes - metabolism Brain Humans Mitochondria Neurons - physiology Serial blockface scanning electron microscopy (SBF-SEM) Synapses Synapses - metabolism Synaptic-like microvesicles Three-dimensional reconstruction Synaptic-like microvesicles Mitochondria Astrocyte network Aldh1l1-eGFP Three-dimensional reconstruction Serial blockface scanning electron microscopy (SBF-SEM) Synapses
Online Access:	Get full text
Tags:	Add Tag No Tags, Be the first to tag this record!

Description
Summary:	The complexity of astrocyte morphology and syncytial coupling through gap junctions are crucial for astrocyte function in the brain. However, the ultrastructural details of astrocyte arborization and interactions between neighboring astrocytes remain unknown. While a prevailing view is that synapses selectively contact peripheral astrocyte processes, the precise spatial-location selectivity of synapses abutting astrocytes is unresolved. Additionally, knowing the location and quantity of vesicles and mitochondria are prerequisites to answer two emerging questions - whether astrocytes have a signaling role within the brain and whether astrocytes are highly metabolically active. Here, we provided structural context for these questions by tracing and 3D reconstructing three neighboring astrocytes using serial block-face scanning electron microscopy. Our reconstructions reveal a spongiform astrocytic morphology resulting from the abundance of reflexive and leaflet processes. At the interfaces, varying sizes of astrocyte-astrocyte contacts were identified. Inside an astrocyte domain, synapses contact the entire astrocyte, and synapse-astrocyte contacts increase from soma to terminal leaflets. In contrast to densely packed vesicles at synaptic boutons, vesicle-like structures were scant within astrocytes. Lastly, astrocytes contain dense mitochondrial networks with a mitochondrial volume ratio similar to that of neurites. Together, these ultrastructural details should expand our understanding of functional astrocyte-astrocyte and astrocyte-neuron interactions. •Astrocytes display spongiform morphology evolving from reflexive/leaflet processes.•Ultrastructural view of astrocyte-astrocyte contacts.•Ultrastructural view of spatial-location selectivity of astrocyte-synapse contacts.•Vesicle-like structures are scant throughout reconstructed astrocyte-connectome.•Astrocytes contain a dense mitochondrial network.
Bibliography:	ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 Emily P. Arzola (Data curation, Formal analysis, Investigation, Methodology, Validation, Visualization, Writing-review and editing) Ahlam Hegazi (Data curation, Writing-review and editing) These authors contributed equally to this study Yixing Du (Data curation, Validation, Writing-review and editing) Merna Philip (Data curation, Writing-review and editing) Kelsey Collins (Data curation, Writing-review and editing) Min Zhou (Conceptualization, Formal analysis, Funding acquisition, Investigation, Methodology, Project administration, Resources, Supervision, Validation, Visualization, Writing-original draft, Writing-review and editing). Rahul Kumar (Data curation, Writing-review and editing) Devin Mediratta (Data curation, Writing-review and editing) Sydney Aten (Conceptualization, Data curation, Formal analysis, Funding acquisition, Investigation, Methodology, Validation, Visualization, Writing-original draft, Writing-review and editing) Jeremy A. Patterson (Investigation, Methodology, Resources, Software, Visualization, Writing-review and editing) Author Contributions Silvana A. Garcia (Data curation, Writing-review and editing) Anne T. Taylor (Data curation, Formal analysis, Writing-review and editing) Elizabeth Gerviacio Camacho (Data curation, Writing-review and editing) Lindsey Trank (Data curation, Writing-review and editing) Emily Benson (Data curation, Resources, Software, Validation, Writing-review and editing) Aiden N. Drake (Data curation, Writing-review and editing) Present address: Department of Neurology, Division of Sleep Medicine, and Program in Neuroscience, Harvard Medical School, Beth Israel Deaconess Medical Center, Boston, MA, USA. Grahame Kidd (Data curation, Resources, Software, Supervision, Validation, Writing-review and editing) Kirsten Boni (Data curation, Writing-review and editing) Conrad M. Kiyoshi (Conceptualization, Data curation, Formal analysis, Investigation, Methodology, Validation, Visualization, Writing-original draft, Writing-review and editing) Present address: Northern Marianas College, Saipan, MP, USA. Present address: Case Western Reserve University School of Medicine., Cleveland, OH, USA. Ally M. Guiher (Data curation, Writing-review and editing) David Terman (Conceptualization, Formal analysis, Funding Acquisition, Investigation, Methodology, Resources, Software, Validation, Visualization, Writing-review and editing)
ISSN:	0301-0082 1873-5118
DOI:	10.1016/j.pneurobio.2022.102264