Cocaine And Amphetamine Regulated Transcript (CART)

CART is a neuropeptide which also serves as a neurotransmitter. It produces similar behaviour in animals to cocaine and amphetamine, but conversely blocks the effects of cocaine when they are co-administered. The peptide is found in several areas, among them the ventral tegmental area (VTA) of the brain. When CART is injected into rat VTA, increased locomotor activity is seen, which is one of the signs of "central stimulation" caused by substances such as cocaine and amphetamine. The rats also tended to return to the place where they had been injected. This is called conditioned place preference and is seen after injection of cocaine. CART is found at the same locations where cocaine and methamphetamine mainly act in the brain. This has led to speculation that CART could be an "endogenous cocaine".