Dopaminergic Modulation of Medial Prefrontal Cortex Deactivation in Parkinson Depression

Figure 5

(a) Illustrating a hypothetical inverted-U dependence of frontal lobe function on dopaminergic medication associated with individual variation in baseline dopamine level. (b) Nondepressed PD patients (red) are positioned at the upstroke lower end of the curve: they reduce their level of VMPFC deactivation and increase VLPFC activation with levodopa medication. Depressed PD patients (blue) are positioned at the downstroke upper end of the curve: they increase their level of VMPFC deactivation and decrease VLPFC activation with levodopa medication. Labels a, b, c, and d indicate representative ndPD and dPD patients; open symbols denote the VMPFC and closed symbols the VLPFC brain regions; dashed lines represent the activity gap off dopaminergic medication, while solid lines represent that on levodopa.

(a)

(b)