A life support system for stimulation of and recording from rodent neuron networks grown on multi-electrode arrays

One promising approach to studying how large numbers of neurons interact is the combination of neuronal cell cultures with multi-electrode arrays (MEAs.) Together, these allow simultaneous recording from many neurons. A particular challenge has been the long-term growth of organotypic neuronal cultures on MEAs. These cultures need alternate exposure to air and a liquid growth medium. Continuous rotary motion (of suitable closed chambers) provides this, but greatly complicates recording of large numbers of low-level electrical signals. An alternative approach is to rock chambers incorporating MEAs cyclically through a limited angle, thus facilitating direct connections. A variable speed trajectory balances cycle frequency against the shear forces acting to dislodge the tissue. Different trajectories can be used to optimize culture health during different development periods. We discuss the design of a microprocessor based life-support system that implements such a limited-angle, variable-speed cycle to culture rat brain slices on MEAs, while maintaining direct electrical connections. We show some of the neurophysiological results thus made possible, and consider improvements for a subsequent life-support system for future research.