Increased dopamine release in the human amygdala during performance of cognitive tasks

Accumulating data support a critical involvement of dopamine in the modulat ion of neuronal activity related to cognitive processing. The amygdala is a major target of midbrain dopaminergic neurons and is implicated in learnin g and memory processes, particularly those involving associations between n ovel stimuli and reward. We used intracerebral microdialysis to directly sa mple extracellular dopamine in the human amygdala during the performance of cognitive tasks. The initial transition from rest to either a working memo ry or a reading task was accompanied by significant increases in extracellu lar dopamine concentration of similar magnitude. During a sustained word pa ired-associates learning protocol, increase in dopamine release in the amyg dala related to teaming performance. These data provide evidence for sustai ned activation of the human mesolimbic dopaminergic system during performan ce of cognitive tasks.