Molecular mechanisms of working memory.

Working memory is a process for temporary active maintenance of information and the role of prefrontal cortex in this memory has been known since the pioneering experiments of Fulton in the early 20th century. Sustained firing of prefrontal neurons during the delay period is considered the neural correlate of working memory. Evidence in literature suggests the involvement of areas beyond the frontal lobe and illustrate that working memory involves parallel, distributed neuronal networks. Prefrontal cortex is part of a complex neural circuit that includes both cortical and subcortical components and many of these regions play vital roles in working memory function. In this article, we review the current understanding of the neural mechanisms of memory maintenance in the brain.