Stroke on a Chip: Spatial and Temporal Control of Oxygen for in vitro Brain Slices

The hippocampal acute brain slice preparation is an excellent model for studying how neuronal tissue responds to a hypoxic insult, a fundamental question to stroke research. However, current techniques are unable to accurately control the oxygen environment in a way that localized stimuli can be administered. To address this problem, we have developed a microfluidic add-on to a commercially available perfusion chamber that diffuses oxygen throughout a thin membrane and directly to the brain slice. A microchannel is responsible for rapid and efficient oxygen delivery and can be modified to allow different regions of the slice to experience different oxygen stimuli. Using this novel device, we show that we can obtain a stable oxygen environment through out the brain slice and better control over the hypoxic insult as demonstrated with the use of the calcium-indicator Fura-2. Finally, we show that we can independently oxygenate different regions of the hippocampus and measure two independent responses, which is not possible with current techniques.