The endoplasmic reticulum in perisynaptic astrocytic processes: shape, distribution and effect on calcium activity
Castillo, María Fernanda Veloz
De Schutter, Erik
KAUST DepartmentBiological and Environmental Science and Engineering (BESE) Division
Permanent link to this recordhttp://hdl.handle.net/10754/677952
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AbstractAstrocytes recently emerged as key regulators of information processing in the brain. Ca2+ signals in perisynaptic astrocytic processes (PAPs) notably allow astrocytes to fine-tune neurotransmission at so-called tripartite synapses. As most PAPs are below the diffraction limit, their content in Ca2+ stores and the contribution of the latter to astrocytic Ca2+ activity is unclear. Here, we reconstruct tripartite synapses in 3D from electron microscopy and find that 75% of PAPs contain some endoplasmic reticulum (ER), a major astrocytic Ca2+ store, displaying strikingly diverse geometrical properties. To investigate the role of such spatial properties, we implemented an algorithm that creates 3D PAP meshes of various ER distributions and constant shape. Reaction-diffusion simulations in those meshes reveal that astrocyte activity is shaped by a complex interplay between the location of Ca2+ channels, Ca2+ buffering, ER shape and distribution. Overall, this study sheds new light into mechanisms regulating signal transmission in the brain.
CitationDenizot, A., Castillo, M. F. V., Puchenkov, P., Calì, C., & De Schutter, E. (2022). The endoplasmic reticulum in perisynaptic astrocytic processes: shape, distribution and effect on calcium activity. https://doi.org/10.1101/2022.02.28.482292
SponsorsThis work used the computing resources of the Scientific Computing and Data Analysis section from the Okinawa Institute of Science and Technology. We thank Iain Hepburn and Weiliang Chen of the Computational Neuroscience Unit, OIST, Okinawa, Japan for discussion and advice on STEPS software. We thank Pierre Magistretti (KAUST, Thuwal) for the financial support to MFVC and to CC, and Graham Knott for kindly sharing the original EM dataset. The work from AD was supported by a JSPS (Japan Society for the Promotion of Science) Standard Postdoctoral Fellowship for Research in Japan (21F21733).
PublisherCold Spring Harbor Laboratory