Fig. 3.

Taste ‘liking’ reactions and contrast map of nucleus accumbens hotspots. Positive ‘liking’ reactions to pleasant sweet tastes shared by human newborn, young orangutan, and adult rat (tongue protrusion; left top), and aversive ‘disliking’ reactions to unpleasant bitter tastes (gape; left bottom). Opioid hotspots and coldspots in the nucleus accumbens (medial shell region shown in sagittal view; right). Green; the entire medial shell mediates opioid-stimulated increases in ‘wanting’ for food reward. Red; only a cubic-millimeter sized hedonic hotspot generates increases in ‘liking’ for the same opioid stimulation. Blue; opioid stimulation of a small hedonic ‘coldspot’ suppresses ‘liking’ reactions to sucrose, whereas a larger purple zone suppresses ‘disliking’ reactions to quinine, all while stimulating food intake. Reprinted by permission from [55], based on data from [53].