Roles of intracortical inhibition in the formation of spatially tuned delay-period activity of prefrontal cortical neurons: computational study

The results suggest that the parallel inhibition regulates the level of the delay-period activity, while the anti-parallel inhibition contributes to the sharpening of the activity profile in the delay period.

Abstract

1. This paper proposes a computational circuit model of the prefrontal cortex, with which computer simulations of the delay-period activity of the prefrontal cortical neurons are made. 2. The aim of this study is to address the question as to how the two types of local inhibition (the parallel inhibition and the anti-parallel inhibition), which were suggested previously and are assumed in this model, contribute to the formation of spatially tuned delay-period activity. 3. The results suggest that the parallel inhibition regulates the level of the delay-period activity, while the anti-parallel inhibition contributes to the sharpening of the activity profile in the delay period. 4. This study found a new prediction that the weakened parallel inhibition causes stronger anti-parallel inhibition of the inactive pyramidal cells due to the disinhibition of the active pyramidal cells. 5. These results suggest the important roles of the intracortical inhibition in the formation and maintenance of spatial working memory.