Comparison of Recordings from Microelectrode Arrays and Single Electrodes in the Visual Cortex

Advances in microelectrode neural recording systems have made it possible to record extracellular activity from a large number of neurons simultaneously. A substantial body of work is associated with traditional single-electrode extracellular recording, and the robustness of the recording method has been proven experimentally. However, the recordings are limited to a small number of cells at a time, so much of the work has relied on compiling population statistics across many recording sessions. Multielectrode recording systems theoretically have some major advantages over this paradigm. They increase the yield of neurons per recording session, and analysis of pairwise correlation benefits greatly from simultaneously recording from a large number of neurons (the number of pairs is proportional to the square of the number of cells). The larger population also provides the possibility of examining higher-order (non-pairwise) interactions among neurons (Schneidman et al., 2006Go; Shlens et al., 2006Go). Finally, multielectrode systems have been developed that may be implanted and used for several months, which permits the study of learning in cell populations. Here we assess this experimental approach for anesthetized acute preparations and compare the quality of recordings to those provided by the traditional single-electrode method.