Adoption of microfluidic MEA technology for electrophysiology of 3D neuronal networks exposed to suborbital conditions.

Studying neuronal cells in space reveals how microgravity affects brain function, gene expression, and cellular processes. This study details the preparation and validation of a 3D neuronal electrophysiology (EPHYS) sensing microfluidic biodevice used during a suborbital space flight. Initially, the device's function was tested with rat hippocampal neurons using EPHYS data collected via a microelectrode array (MEA). This system was later applied to human glutamatergic (Glu) neurons for eight days preceding a suborbital flight. A live-dead assay confirmed cell viability, and the system was integrated into a CubeLab to maintain a controlled environment. Two biological samples were flown, along with two control samples, to validate the EPHYS system. Results showed that human Glu-neurons exposed to microgravity exhibited altered expression of vesicular glutamate transporters (VGLUTs) while maintaining neuronal differentiation markers. The findings contribute to understanding neurological disorders, neuro-inflammation, and cognitive impacts of space travel, with broader applications for brain health research on Earth.