Electrical Imaging: Investigating Cellular Function at High Resolution.

Electrical imaging of extracellular potentials reveals the activity of electrogenic cells and of networks thereof over several orders of magnitude, both in space and time. On a spatial scale, electrical activity propagates in nanometer-sized nerve fibers (axons, dendrites), which connect cells in a biological network over several millimeters. On a temporal scale, changes of the extracellular potential caused by action potentials occur on a sub-millisecond scale, while network activity may be modulated over seconds. Here, different electrode arrays are described, which are designed to image modulations of the electrical potentials over a wide spatiotemporal range. In the second part, typical applications and scientific questions in neuroscience research addressed so far are reviewed. The review ends with an outlook on expected developments.