Attention deficit hyperactivity disorder management
There are two major medications derived from methylphenidate's isomers: a racemic mixture of half d-threo-methylphenidate and half l-threo-methylphenidate called methylphenidate (Ritalin, Concerta), and an enantiopure formulation containing just d-threo-methylphenidate called dexmethylphenidate (Focalin).
Cocaine and amphetamine regulated transcript
CART is a neuropeptide that 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 tend to return to the place where they were injected. This is called conditioned place preference and is seen after injection of cocaine.