FBS Colloquia No.347Dynamic Brain Network Laboratory

Novel mechanisms of working memory in the frontal-parietal lobes that do not depend on sustained firing

According to a long-standing theory, the short-term retention of information in working memory (WM) is carried out by the sustained firing of neurons in the lateral prefrontal cortex (LPFC). In this theory, WM differs from long-term memory in that it does not involve changes in the efficiency of synaptic transmission within the neural circuit (chemical changes) or the reconnection of the circuit itself (morphological changes) through spine stretching and synaptogenesis, but depends only on neuronal firing (electrical activity). Recently, however, we have discovered a behavior of LPFC neurons in working memory that is very different from this; the population of neurons in the LPFC appear to use two different mechanisms depending on the situation: (1) retention by sustained firing and (2) retention that does not depend on sustained firing. In this talk, I will introduce a series of our recent studies which highlighted the importance of the latter mechanisms, and discuss how these findings will contribute to a fuller understanding of this new retention mechanism in working memory.