Precise Dynamic Control of Tissue Oxygenation during Brain Slice Electrophysiology.

Jurado A, Pérez-González AP, Farré R, Gozal D, Gasull X, Almendros I

American Journal of Physiology-Cell Physiology, in press.       doi.org/10.1152/ajpcell.00846.20

 

ABSTRACT

Precise oxygen regulation is essential for maintaining neuronal integrity in ex vivo brain slice electrophysiology, yet conventional chambers provide poorly defined oxygenation. This limitation is particularly problematic when model neurological disorders characterized by transient or intermittent hypoxia (IH), such as transient ischemic attacks and sleep apnea. We aimed to develop an open-source versatile Oxyslice Recording Chamber (ORC) enabling real-time monitoring of neural activity with rapid, precise oxygen modulation during standard recordings. A polydimethylsiloxane (PDMS)-based ORC comprising a gas-permeable membrane that separates the recording and gas chambers was developed, allowing rapid and uniform oxygen exchange. The device integrates seamlessly into standard electrophysiological setups and operates at low perfusion rates. The device was used for sujecting mouse hippocampal slices to continuous and intermittnt hypoxia while recording field excitatory postsynaptic potentials. The ORC achieved precise, reproducible control of oxygen at the cellular level. Both CH and IH induced hypoxia severity–dependent eltropfhysiologial alterations, fully reversed upon reoxygenation. This novel ORC provides a robust, adaptable method for real-time oxygen modulation in ex vivo neuronal standard recordings. Its ability to model continuous and intermittent hypoxia at physiological oxygen tensions fills a major gap in current electrophysiological methodologies, opening new opportunities for mechanistic studies of hypoxia-driven dysfunction and therapeutic discovery.