Association between striatal dopamine D2/D3 receptors andbrain activation during visual attention: effects of sleep deprivation

摘要

Sleep deprivation (SD) disrupts dopamine (DA) signaling and impairs attention. However, the interpretation of these concomitant effects requires a better understanding of dopamine’s role in attention processing. Here we test the hypotheses that D2/D3 receptors (D2/D3R) in dorsal and ventral striatum would distinctly regulate the activation of attention regions and that, by decreasing D2/D3, SD would disrupt these associations. We measured striatal D2/D3R using positron emission tomography with [¹¹C]raclopride and brain activation to a visual attention (VA) task using 4-Tesla functional magnetic resonance imaging. Fourteen healthy men were studied during rested wakefulness and also during SD. Increased D2/D3R in striatum (caudate, putamen and ventral striatum) were linearly associated with higher thalamic activation. Subjects with higher D2/D3R in caudate relative to ventral striatum had higher activation in superior parietal cortex and ventral precuneus, and those with higher D2/D3R in putamen relative to ventral striatum had higher activation in anterior cingulate. SD impaired the association between striatalD2/D3R and VA-induced thalamic activation, which isessential for alertness. Findings suggest a robust DAergic modulation of corticalactivation during the VA task, such that D₂/D₃R in dorsalstriatum counterbalanced the stimulatory influence ofD₂/D₃R in ventral striatum, which was not significantlydisrupted by SD. In contrast, SD disrupted thalamic activation, which did not showcounterbalanced DAergic modulation but a positive association withD₂/D₃R in both dorsal and ventral striatum. Thecounterbalanced dorsal versus ventral striatal DAergic modulation of VA activationmirrors similar findings during sensorimotor processing (Tomasi et al.,2015) suggesting a bidirectional influence in signaling between the dorsal caudateand putamen and the ventral striatum.