ventral tegmental area

An unpaired midbrain region in the ventromedial portion of the reticular formation, the ventral tegmental area is bounded by identifiable neighbours: it lies medial to the substantia nigra and ventral to the red nucleus, and extends caudally from the posterior hypothalamus of the diencephalon. It contains dopamine neurons whose axons project to various limbic and cortical areas, and on that basis it is described as a critical component of the brain's reward circuitry. Its unpaired midline position distinguishes it from the paired dopaminergic cell group of the substantia nigra alongside it, and its designation a10a places it within the numbered catecholamine cell groups of the brainstem.