Researchers at SRI International and Astraea Therapeutics have identified a new drug receptor that could help in treating drug addiction.
The receptor, called alpha4beta2, is part of the nicotinic acetylcholine receptors (nAChRs), which is already recognised as being largely responsible for addiction to nicotine. Varenicline is therefore the drug that is generally used in therapeutic treatment.
A lesser-known subtype, called alpha3beta4 nAChR, is now being studied in the same acetylcholine receptors, and is thought to play a prominent part in the addictive properties of cocaine, morphine, and nicotine. Astraea Therapeutics have developed AT-1001, which has shown to be successful in preliminary studies at reducing nicotine withdrawal symptoms such as anxiety.
Drugs are addictive because they work on the reward circuit of the brain, which makes them feel both pleasurable and acceptable. Dopamine is the key neurotransmitter in this circuit, and the researchers believe that by disrupting the alpha3beta4 nAChR system using selective drugs, the reward circuitry may be cut-off.
Taline Khroyan, Ph.D., Senior Behavioral Pharmacologist in SRI's Center for Health Sciences said: "Currently, there are no therapeutics approved to treat addiction to stimulants such as cocaine, so it is intriguing to find a promising drug receptor target and to see that AT-1001 can indeed affect phenomena that are thought to be deeply tied to the addictive nature of cocaine and other drugs of abuse."