The concepts for neuronal coding during short-term or working memory have recently been challenged by observations that do no longer support an exclusive role of sustained firing in maintaining information. We have studied alternative neural signals like LFP oscillations and higher order spike synchronization which reveal interesting options for engaging cortical circuitry in the maintenance of information about stimuli in short-term memory. I will discuss our findings in the light of multiple oscillatory rhythms and measures of global system dynamics which may serve as coordinating principles of memory processes.