“…Not surprisingly, a large majority focused on the mesocorticolimbic dopaminergic pathway: the NAc (21 articles [8,22,26,28–30,32,40–53]), frontal cortex (13 articles [8,25,27,29,51,54–61]), whole/unspecified striatal complex (11 articles [24,33,62–70]), dorsal striatum (7 articles [8,30,48–50,71,72]) and ventral tegmental area (VTA, 5 articles [28,51,73–75]). Other regions included the spinal cord (7 articles [62,76– 81]); hippocampus (5 articles [8,63,82–84]); amygdala (3 articles [8,85,86]); locus coeruleus [74, 87], ventral midbrain [42, 88], hypothalamus [89, 90], whole brain with [91] or without [92] cerebellum (1 each); periaqueductal gray matter [93], pituitary gland [90], arcuate nucleus [94], nucleus of the tractus solitarius [31], brainstem [23], cerebellum [84] or dorsal root ganglia [95] (DRG, 1 each). Below, we briefly describe the rationale for studying such diverse structures.…”