Editing Ventral tegmental area (section)

=== Reward system ===

The dopamine reward circuitry in the human brain involves two projection systems from the ventral midbrain to the nucleus accumbens-[[olfactory tubercle]] complex.  First, the posteromedial VTA and central linear raphe cells selectively project to the [[ventral striatum|ventromedial striatum]], which includes the medial olfactory tubercle and the medial [[nucleus accumbens shell|NAC shell]].  Second, the lateral VTA projects largely to the ventrolateral striatum, which includes the [[nucleus accumbens core|NAC core]], the medial NAC shell, and the lateral olfactory tubercle. These pathways are called the meso-ventromedial and the meso-ventrolateral striatal dopamine systems, respectively. The medial projection system is important in the regulation of arousal characterized by affect and drive and plays a different role in goal-directed behavior than the lateral projection system. Unlike the lateral part, the medial one is activated not by rewarding but by noxious stimuli.<ref name="pmid17574681">{{cite journal | vauthors = Ikemoto S | title = Dopamine reward circuitry: two projection systems from the ventral midbrain to the nucleus accumbens-olfactory tubercle complex | journal = Brain Research Reviews | volume = 56 | issue = 1 | pages = 27–78 | date = November 2007 | pmid = 17574681 | pmc = 2134972 | doi = 10.1016/j.brainresrev.2007.05.004 }}</ref><ref name="pmid19261850">{{cite journal | vauthors = Brischoux F, Chakraborty S, Brierley DI, Ungless MA | title = Phasic excitation of dopamine neurons in ventral VTA by noxious stimuli | journal = Proceedings of the National Academy of Sciences of the United States of America | volume = 106 | issue = 12 | pages = 4894–9 | date = March 2009 | pmid = 19261850 | pmc = 2660746 | doi = 10.1073/pnas.0811507106 | bibcode = 2009PNAS..106.4894B | doi-access = free }}</ref> Therefore, the NAC shell and the posterior VTA are the primary areas involved in the reward system.{{citation needed|date=April 2015}}