Close-up of glutamatergic (green) and GABAergic (red) neurotransmission under normal conditions and in the presence of LY341495 (LY, blue), which blocks presynaptic mglu2/3 receptors and consequently enhances release of both glutamate and GABA from their respective neurons (insets). Glutamatergic inputs (green) are shown from medial prefrontal cortex, orbitofrontal cortex, hippocampus, thalamus, and basolateral amygdale. GABAergic medium spiny neurons (deep red) and GABAergic inputs (red) to NAc shell are shown from ventral pallidum and ventral tegmental area. Dopaminergic inputs are shown from the ventral tegmental area (black). Circuit diagram is modified from Faure et al., 2010, with inset based on Swanson et al., 2005.