were enhanced by dopamine even at concentrations as low as 100nM. Dopamine also enhanced the ability of stimulus-evoked EPSPs to induce firing when these events were generated during an up-state. This effect was concentration dependent as up-state duration and spiking were unaffected by 10 nM DA but were inhibited by 10 µM DA. These data are consistent with dopamine’s role in tuning PFC function during working memory tasks and support the idea that dopamine’s actions are optimal over a narrow concentration range (Goldman-Rakic, 1999).
