Leader neurons drive spontaneous and evoked activation patterns in cortical networks

Abstract

Recent studies about the generation and propagation of coordinated activity in cultured neuronal networks reported the existence of privileged neurons that consis-tently fire earlier than others at the onset of synchro-nized bursting events (or network bursts, NB), which have been termed major burst leaders (MBL) [1]. At the same time, by stimulating the network from different channels one can obtain very different responses, not only in size and delay but also in the activation order of the responding neurons [2]. We electrically stimulated rat cortical networks cultured on micro-electrode arrays from different locations, either MBL or non-MBL. We evaluated the intensity and the delay of responses from either MBL or non-MBL and we