A Review of the Physiological Role of Hypocretin in the Ventral Tegmental Area in Reward and Drug Dependence

Orexin (OX, hypocretin: HCRT) as a neuropeptide is produced in a distinct population of neurons in the posterior lateral hypothalamus (LH). OX neurons implicate in reward function. OX makes a main input from the hypothalamus to the ventral tegmental area (VTA) of the midbrain. OX, through OX receptors (OXR1, OXR2) activates VTA dopamine (DA) neurons. VTA neurons are involved in reward processing and motivation. In this review, we will discuss the OX effect on addiction through VTA activation and related areas of the brain.