A study co-authored by Oregon Health & Science University researcher Dr David Grandy found a link between dopamine supersensitivity and increased levels of a dopamine receptor with a particularly high affinity for dopamine.
Dopamine is a neurotransmitter found in the brain that plays an important role in the regulation of behavior involved in movement control, motivation and reward, and the dopamine system is thought to be essential to the brain’s response to drugs of abuse, especially opiates and psychostimulants.
Supersensitivity to dopamine, which affects 70% of individuals with schizophrenia, can take the form of a low tolerance to antipsychotics, amphetamines and other drugs, including drugs of abuse, that trigger dopamine’s release in the brain. The latest discovery could someday lead to the development of drug therapies that temporarily bring people with psychosis into a more normal, less-sensitive state and make them more amenable to antipsychotic treatment.
It also could help scientists find ways to turn down the activity of the dopamine D2 receptor in individuals for whom dopamine sensitivity can be dangerous, such as prolonged drug abusers.
“The more we understand about the receptors, their physical characteristics, how they put themselves into this high-affinity state, and then signal this event in the brain, the closer we’ll be to better treating and maybe even preventing the development of psychoses,” said Grandy.