Figure 2.

Hypothetical direct and indirect output pathways whereby the NAc core and shell may disinhibit or inhibit, respectively, adaptive motor pathways for maximizing reward acquisition. Only major projections are shown. Red indicates inhibitory structures and pathways, whereas green indicates excitatory connections. Please refer ‘Efferents' in section Nucleus Accumbens for detailed explanation. BF Hypoth, basal forebrain and hypothalamus; MD Thal, mediodorsal thalamic nucleus; NAc, nucleus accumbens; PFC, prefrontal cortex; SNr, substantia nigra zona reticulata; STN, subthalamic nucleus; VP dl/vm, ventral pallidum, dorsolateral, and ventromedial; VTA, ventral tegmental area.