
==== Front
bioRxiv
BIORXIV
bioRxiv
2692-8205
Cold Spring Harbor Laboratory

10.1101/2024.09.07.610493
preprint
1
Article
Morphological comparison of astrocytes in the lamina cribrosa and glial lamina
Waxman Susannah
Schilpp Hannah
Linton Ashley
Jakobs Tatjana C.
Sigal Ian A. http://orcid.org/0000-0002-0790-7911

10 9 2024
2024.09.07.610493https://creativecommons.org/licenses/by-nc/4.0/ This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License, which allows reusers to distribute, remix, adapt, and build upon the material in any medium or format for noncommercial purposes only, and only so long as attribution is given to the creator.
http://biorxiv.org/lookup/doi/10.1101/2024.09.07.610493
nihpp-2024.09.07.610493.pdf
Abstract

Purpose

Although the mechanisms underlying glaucomatous neurodegeneration are not yet well understood, cellular and small animal models suggest that LC astrocytes undergo early morphologic and functional changes, indicating their role as early responders to glaucomatous stress. These models, however, lack the LC found in larger animals and humans, leaving the in situ morphology of LC astrocytes and their role in glaucoma initiation underexplored. In this work, we aimed to characterize the morphology of LC astrocytes in situ and determine differences and similarities with astrocytes in the mouse glial lamina (GL), the analogous structure in a prominent glaucoma model.

Methods

Astrocytes in the LCs of twenty-two eyes from goats, sheep, and pigs were stochastically labeled via Multicolor DiOlistics and imaged in situ using confocal microscopy. 3D models of DiOlistically-labeled LC astrocytes and hGFAPpr-GFP mouse GL astrocytes were constructed to quantify morphological features related to astrocyte functions. LC and GL astrocyte cross-pore contacts, branching complexity, branch tortuosity, and cell and branch span were compared.

Results

LC astrocytes displayed distinct spatial relationships with collagen, greater branching complexity, and higher branch tortuosity compared to GL astrocytes. Despite substantial differences in their anatomical environments, LC and GL astrocytes had similar cell and branch spans.

Conclusions

Astrocyte morphology in the LC was characterized through Multicolor DiOlistic labeling. LC and GL astrocytes have both distinct and shared morphological features. Further research is needed to understand the potentially unique roles of LC astrocytes in glaucoma initiation and progression.
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pmc
