CART in energy balance and drug addiction: Current insights and mechanisms.

Cocaine amphetamine related transcript (CART) is a neuropeptide first isolated and sequenced from ovine hypothalamus and later shown to have functions related to drug taking, drug seeking, and energy balance. Here we review the molecular features of CART, its anatomical distribution and provide an update on CART function in energy balance control and addiction. A common theme across these topics is that CART has diverse roles and functions depending on both the specific cells in which it is expressed as well as the location of these cells in distinct midbrain, hypothalamic, thalamic, and striatal circuits. Although understanding of the functions of CART in addictive behaviors has been hampered by lack of appropriate receptor antagonists, the recent characterization of a putative CART receptor and the availability of better genetic tools to access to the CART system will help answer longstanding questions in this field.