FIGURE 1.

Corticolimbic circuits and the main components of the reward circuitry are illustrated. Red lines: the nucleus accumbens (NAc) receives afferent nociceptive information mainly via connections with the anterior cingulate cortex (ACC), amygdala (Amy), thalamus, and parabrachial nucleus (PB). Possible direct connections from the spinal cord to the NAc (red dotted line) are also shown. Blue lines: corticostriatal projections arising from the prefrontal cortex (PFC) and ACC. The connections between the Amy, thalamus and ventral tegmental area (VTA) and the NAc are also represented by blue lines. The descending pathway from the NAc to the spinal cord, that putatively regulates nociceptive information, probably through the rostral ventromedial medulla (RVM), is represented by a gold dotted line. Adapted by permission from Macmillan Publishers Ltd: Nature Neuroscience (Navratilova and Porreca, 2014), copyright 2014.