More than three decades of research into the neurobiological substrates of reward have focused attention on the nucleus accumbens (NAc), a ventromedial component of the basal ganglia, as a key structure in the neural systems responsible for translating motivation to action [1–4]. The preponderance of this research effort has centered on dopamine (DA) as the primary neurotransmitter in this regard. Many laboratories have contributed to our understanding of the role of DA in motivated behavior, and certainly the efforts of Dr. Bartley Hoebel in his laboratory at Princeton have been particularly noteworthy. Studies by Hoebel and colleagues have demonstrated increases in the release of DA in the NAc as a function of a variety of behaviors including feeding [5,6], rehydration [7], models of binge eating [8,9] and hypothalamic stimulation [10]. Moreover, his laboratory has been instrumental in demonstrating that many drugs with abuse liability (including cocaine, amphetamine, opiates, nicotine and alcohol) share a common mechanism in their ability to elevate DA levels in the NAc.
