Cortical recording with polypyrrole microwire electrodes.

The ability to record from the same neuron for extended periods of time is essential to understanding how the brain reorganizes during learning. Conventional chronic recording microelectrodes are made from metal or silicon. However, the large stiffness mismatch between the electrodes and brain tissue causes shear-induced inflammation, limiting long-term recording stability. The flexibility of polypyrrole microwire has the potential to improve the chronic recording stability by minimizing the stiffness mismatch. In this paper, we report the implantation of a conducting polymer microwire electrode in a rodent brain, and the successful recording of cortical activity using such an electrode.