Verification of Microgravity Simulation on Earth with neuronal cells

Abstract

This study aimed to verify the efficacy of clinostat-based microgravity simulation for adherent cells, by using primary murine astrocytes as a model system. Particle Image Velocimetry analysis revealed complex fluid dynamics during clinorotation, with a stable rotation phase characterized by low fluid velocities and minimal shear stress. Astrocyte morphology and reactivity were examined under normal gravity (1g) and simulated microgravity (s-ug) conditions over a time interval of five days. While no significant differences in cell area were observed between s-ug and 1g conditions, nuclear morphology showed itme- and position-dependent alterations, including nuclear elongation under s-ug. Astrocyte reactivity, assessed by GFAP expression, significantly increased under s-ug conditions, with edge regions showing a more pronounced effect. The proportion of GFAP-positive cells increased from 18-21 % in 1g controls to 30-36 % under s-ug ager 1-5 days of exposure. GFAP fluorescence intensity exhibited a biphasic response, with an initial decrease followed by a significant increase from day 2 onwards. These findings highlight the complex cellular responses to simulated microgravity and underscore the need for further investigation to distinguish between simulated microgravity effects and responses to potential other forces acting during clinorotation. This study contributes valuable insights into cellular space biology research and improves the understanding of how central nervous system cells respond to altered gravity conditions.