Modulating neural networks dynamics: multi-site electrical stimulation of in-vitro cortical neurons coupled to MEA devices

Networks of neurons extracted from the developing central nervous system (CNS) are spontaneously active and show a typical electrophysiological pattern called "burst". In vitro cultured neurons represent a simplified level of organization where the collective and functional electrophysiological properties emerge and can be experimentally characterized for a better understanding on how brain processes information. Using microelectrode arrays (MEA), on which a cell culture can be grown and kept alive for a long time (from weeks up to months), we recorded the electrophysiological activity of cortical cultures of neurons extracted from an embryonic rat. This activity pattern can be, at some extent, modified by an electrical manipulation, in order to define distinct functional collective states of the network related to specific pattern of stimulation delivered through the network. In order to represent these behaviors from a quantitative point of view, we described the network activity both at burst and at spike level, analyzing the electrophysiological pattern under different stimulation conditions and providing information about network behavior employing custom developed algorithms of burst analysis and standard statistical procedures for spike analysis.