Astrocyte morphology

Dissecting Reactive Astrocyte Responses: Lineage Tracing and Morphology-based Clustering

“…The study of astrocytes encompasses various dimensions including regional, molecular, and biochemical aspects, developmental stages, interspecies adaptations, aging, brain damage, and neurological conditions (Escartin et al, 2019;Khakh et Deneen, 2019;Matias et al, 2019;Pestana et al, 2020;Bayraktar et al, 2020;Falcone et al, 2021;Endo et al, 2022). From pioneering works in glia biology (Virchow 1846;Cajal, 1913;Somjen, 1988) to the most recent state-of-the-art compilation papers (Endo et al, 2022;Baldwin et al, 2023;Verkhratsky et al, 2023), we now understand that the size, shape, and complexity of astrocytes are intimately linked to their functional status and their capacity to interact with diverse neural and non-neural cells.…”

“…Currently, various measurements are used to assess astrocyte morphological changes that could correlate to their function in response to injury. Unfortunately, most of these analyses encounter limitations due to the inherent constraints of microscopes in resolving parameters such as the overall complexity of 3D branching in astrocytes, including their finer processes like branchlets and leaflets (Baldwin et al, 2023). In this work, and despite encountering interindividual variability values for most of the sizerelated parameters (CV values), our approach using the StarTrack labeling technique in conjunction with a thoughtful morphological analysis, resulted in a pioneer method of analysis to correlate morphological changes in astrocyte subpopulations such as their shape, size, or a combination of both factors with their function measured as intensity of astrocyte response to an injury.…”

“…Of note, we also included Sholl components "intersections", "radius" and "complexity", that correspond with the number of times a branch "intersects" imaginary concentric circles at a given "radius", centered on the soma (Sholl intersections profile). As a result, Sholl analysis give a one-dimensional profile ("complexity") of astrocyte branching allowing the comparison of branches density and spatial distribution (Sholl, 1953;Bird et Cuntz., 2019;Baldwin et al, 2023).…”

“…However, major questions regarding astrocyte morphology changes in relation to injury such as how astrocytes acquire their shapes, whether and how these changes alter neuron-glia interactions, or whether astrocyte changes contribute to the disease causation and progression, remain unknown (Baldwin et al, 2023). Furthermore, the morphological modifications among astrocyte subpopulations, known generally as "astrocyte reactivity", into the local neuroprotective and reparative signaling within damaged neuronal circuits, continue to be largely unstudied.…”

Assessing Different Histological Preparations for Reconstruction of Astrocyte Tridimensional Structure

“…Astrocytes are ubiquitous in the brain and spinal cord and are crucial for circuits function and behavior [ 1 , 2 , 3 , 4 ]. These cells display a complex morphology ranging from multiple main processes stemming from the soma to endfeet and a myriad of leaflets that are in close contact with synapses and other cellular structures [ 5 , 6 , 7 ]. Astrocyte morphology displays regional heterogeneity that is essential for the local interactions with neurons and other cells or tissues [ 8 , 9 , 10 ].…”