Research in the field of neuropsychopharmacology encompasses a wide range of objectives. These might include the study of a new chemical compound for potentially beneficial cognitive or behavioral effects, or the study of an old chemical compound in order to better understand its mechanism of action at the cell and neural circuit levels. For example, the addictive stimulant drug cocaine has long been known to act upon the reward system in the brain, increasing dopamine and norepinephrine levels and inducing euphoria for a short time. More recently published studies however have gone deeper than the circuit level and found that a particular G-protein coupled receptor complex called A2AR-D2R-Sigma1R is formed in the NAc following cocaine usage; this complex reduces D2R signaling in the mesolimbic pathway and may be a contributing factor to cocaine addiction. Other cutting-edge studies have focused on genetics to identify specific biomarkers that may predict an individual's specific reactions or degree of response to a drug or their tendency to develop addictions in the future. These findings are important because they provide detailed insight into the neural circuitry involved in drug use and help refine old as well as develop new treatment methods for disorders or addictions. Different treatment-related studies are investigating the potential role of peptide nucleic acids in treating Parkinson's disease and schizophrenia while still others are attempting to establish previously unknown neural correlates underlying certain phenomena.